task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k |
|---|---|---|---|---|---|
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Python | Python | from turtle import *
def dragon(step, length):
dcr(step, length)
def dcr(step, length):
step -= 1
length /= 1.41421
if step > 0:
right(45)
dcr(step, length)
left(90)
dcl(step, length)
right(45)
else:
right(45)
forward(length)
left(9... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Phix | Phix | with javascript_semantics
function linear_combination(sequence f)
string res = ""
for e=1 to length(f) do
integer fe = f[e]
if fe!=0 then
if fe=1 then
if length(res) then res &= "+" end if
elsif fe=-1 then
res &= "-"
elsif fe>0 ... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Retro | Retro |
# Determine The Average Word Name Length
To determine the average length of a word name two values
are needed. First, the total length of all names in the
Dictionary:
~~~
#0 [ d:name s:length + ] d:for-each
~~~
And then the number of words in the Dictionary:
~~~
#0 [ dr... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #REXX | REXX | /*REXX program illustrates how to display embedded documentation (help) within REXX code*/
parse arg doc /*obtain (all) the arguments from C.L. */
if doc='?' then call help /*show documentation if arg=a single ? */
/*■■■■■■■■■regular■■■■■■■■■■■■■■■■■■■■■■■■■*/
/... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Ring | Ring |
/*
Multiply two numbers
n1: an integer.
n2: an integer.
returns product of n1 and n2
*/
see mult(3, 5) + nl
func mult n1, n2
return n1*n2
|
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #R | R | diversityStats <- function(trueValue, estimates)
{
collectivePrediction <- mean(estimates)
data.frame("True Value" = trueValue,
as.list(setNames(estimates, paste("Guess", seq_along(estimates)))), #Guesses, each with a title and column.
"Average Error" = mean((trueValue - estimates)^2),
... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #Racket | Racket | #lang racket
(define (mean l)
(/ (apply + l) (length l)))
(define (diversity-theorem truth predictions)
(define μ (mean predictions))
(define (avg-sq-diff a)
(mean (map (λ (p) (sqr (- p a))) predictions)))
(hash 'average-error (avg-sq-diff truth)
'crowd-error (sqr (- truth μ))
'diversity... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Action.21 | Action! | INT FUNC DotProduct(INT ARRAY v1,v2 BYTE len)
BYTE i,res
res=0
FOR i=0 TO len-1
DO
res==+v1(i)*v2(i)
OD
RETURN (res)
PROC PrintVector(INT ARRAY a BYTE size)
BYTE i
Put('[)
FOR i=0 TO size-1
DO
PrintI(a(i))
IF i<size-1 THEN
Put(',)
FI
OD
Put('])
RETURN
PROC Test(INT AR... |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Delphi | Delphi |
program Doubly_linked;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
boost.LinkedList;
var
List: TLinkedList<string>;
Head, Tail,Current: TLinkedListNode<string>;
Value:string;
begin
List := TLinkedList<string>.Create;
List.AddFirst('.AddFirst() adds at the head.');
List.AddLast('.AddLast() adds ... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | ClearAll[DisariumQ]
DisariumQ[n_Integer] := Module[{digs},
digs = IntegerDigits[n];
digs = digs^Range[Length[digs]];
Total[digs] == n
]
i = 0;
Reap[Do[
If[DisariumQ[n],
i++;
Sow[n]
];
If[i == 19, Break[]]
,
{n, 0, \[Infinity]}
]][[2, 1]] |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Perl | Perl | use strict;
use warnings;
my ($n,@D) = (0, 0);
while (++$n) {
my($m,$sum);
map { $sum += $_ ** ++$m } split '', $n;
push @D, $n if $n == $sum;
last if 19 == @D;
}
print "@D\n"; |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #PowerShell | PowerShell | $DNS = Resolve-DnsName -Name www.kame.net
Write-Host "IPv4:" $DNS.IP4Address "`nIPv6:" $DNS.IP6Address |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Python | Python | >>> import socket
>>> ips = set(i[4][0] for i in socket.getaddrinfo('www.kame.net', 80))
>>> for ip in ips: print ip
...
2001:200:dff:fff1:216:3eff:feb1:44d7
203.178.141.194 |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #R | R |
#include <Rcpp.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
using namespace Rcpp ;
// [[Rcpp::export]]
CharacterVector getNameInfo(std::string fqdn) {
struct addrinfo hints, *res, *res0;
int error;
char... |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Quackery | Quackery | [ $ "turtleduck.qky" loadfile ] now!
[ 2 *
2dup turn
4 1 walk
turn ] is corner ( n/d --> )
forward is right ( n --> )
forward is left ( n --> )
[ dup 0 = iff
[ drop 8 1 walk ] done
1 - dup
left
1 4 corn... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #PureBasic | PureBasic | ; Process and output values.
Procedure WriteLinear(Array c.i(1))
Define buf$,
i.i, j.i, b,i
b = #True
j = 0
For i = 0 To ArraySize(c(), 1)
If c(i) = 0 : Continue : EndIf
If c(i) < 0
If b : Print("-") : Else : Print(" - ") : EndIf
ElseIf c(i) > 0
If Not b : Print(" + ") : ... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Ruby | Ruby | =begin rdoc
RDoc is documented here[http://www.ruby-doc.org/core/classes/RDoc.html].
This is a class documentation comment. This text shows at the top of the page
for the class.
Comments can be written inside "=begin rdoc"/"end" blocks or
in normal '#' comment blocks.
There are no '@parameters' like javadoc, bu... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Rust | Rust | //! Documentation for the module
//!
//! **Lorem ipsum** dolor sit amet, consectetur adipiscing elit. Aenean a
//! sagittis sapien, eu pellentesque ex. Nulla facilisi. Praesent eget sapien
//! sollicitudin, laoreet ipsum at, fringilla augue. In hac habitasse platea
//! dictumst. Nunc in neque sed magna suscipit mattis ... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Scala | Scala | /**
* This is a class documentation comment. This text shows at the top of the page for this class
*
* @author Joe Schmoe
*/
class Doc {
/**
* This is a field comment for a variable
*/
private val field = 0
/**
* This is a method comment. It has parameter tags (param) and a return value tag ... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #Raku | Raku | sub diversity-calc($truth, @pred) {
my $ae = avg-error($truth, @pred); # average individual error
my $cp = ([+] @pred)/+@pred; # collective prediction
my $ce = ($cp - $truth)**2; # collective error
my $pd = avg-error($cp, @pred); # prediction diversity
return $ae, $ce, $pd;
}
sub a... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #ActionScript | ActionScript | function dotProduct(v1:Vector.<Number>, v2:Vector.<Number>):Number
{
if(v1.length != v2.length) return NaN;
var sum:Number = 0;
for(var i:uint = 0; i < v1.length; i++)
sum += v1[i]*v2[i];
return sum;
}
trace(dotProduct(Vector.<Number>([1,3,-5]),Vector.<Number>([4,-2,-1]))); |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #E | E | def makeDLList() {
def firstINode
def lastINode
def makeNode(var value, var prevI, var nextI) {
# To meet the requirement that the client cannot create a loop, the
# inter-node refs are protected: clients only get the external facet
# with invariant-preserving operations.
... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Phix | Phix | with javascript_semantics
constant limit = 19
integer count = 0, n = 0
printf(1,"The first 19 Disarium numbers are:\n")
while count<limit do
atom dsum = 0
string digits = sprintf("%d",n)
for i=1 to length(digits) do
dsum += power(digits[i]-'0',i)
end for
if dsum=n then
printf(1," %d... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Picat | Picat | main =>
Limit = 19,
D = [],
N = 0,
printf("The first %d Disarium numbers are:\n",Limit),
while (D.len < Limit)
if disarium_number(N) then
D := D ++ [N]
end,
N := N + 1,
if N mod 10_000_000 == 0 then
println(test=N)
end
end,
println(D).
disarium_number(N) =>
Sum... |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Racket | Racket |
#lang racket
(require net/dns)
(dns-get-address "8.8.8.8" "www.kame.net")
|
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Raku | Raku | use Net::DNS;
my $resolver = Net::DNS.new('8.8.8.8');
my $ip4 = $resolver.lookup('A', 'orange.kame.net');
my $ip6 = $resolver.lookup('AAAA', 'orange.kame.net');
say $ip4[0].octets.join: '.';
say $ip6[0].octets.».fmt("%.2X").join.comb(4).join: ':'; |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #R | R |
Dragon<-function(Iters){
Rotation<-matrix(c(0,-1,1,0),ncol=2,byrow=T) ########Rotation multiplication matrix
Iteration<-list() ###################################Set up list for segment matrices for 1st
Iteration[[1]] <- matrix(rep(0,16), ncol = 4)
Iteration[[1]][1,]<-c(0,0,1,0)
Iteration[[1]][2,]<-c(1,0,1,... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Python | Python |
def linear(x):
return ' + '.join(['{}e({})'.format('-' if v == -1 else '' if v == 1 else str(v) + '*', i + 1)
for i, v in enumerate(x) if v] or ['0']).replace(' + -', ' - ')
list(map(lambda x: print(linear(x)), [[1, 2, 3], [0, 1, 2, 3], [1, 0, 3, 4], [1, 2, 0],
[0, 0, 0], [0], [1, 1, 1], [-1, -1... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Smalltalk | Smalltalk | FooClass comment: 'This is a comment ....'. |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #SQL_PL | SQL PL |
CREATE TABLESPACE myTs;
COMMENT ON TABLESPACE myTs IS 'Description of the tablespace.';
CREATE SCHEMA mySch;
COMMENT ON SCHEMA mySch IS 'Description of the schema.';
CREATE TYPE myType AS (col1 INT) MODE DB2SQL;
COMMENT ON TYPE mytype IS 'Description of the type.';
CREATE TABLE myTab (
myCol1 INT NOT NU... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #REXX | REXX | /* REXX */
Numeric Digits 20
Call diversityTheorem 49,'48 47 51'
Say '--------------------------------------'
Call diversityTheorem 49,'48 47 51 42'
Exit
diversityTheorem:
Parse Arg truth,list
average=average(list)
Say 'average-error='averageSquareDiff(truth,list)
Say 'crowd-error='||(truth-average)**2
Say ... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #Ruby | Ruby | def mean(a) = a.sum(0.0) / a.size
def mean_square_diff(a, predictions) = mean(predictions.map { |x| square(x - a)**2 })
def diversity_theorem(truth, predictions)
average = mean(predictions)
puts "truth: #{truth}, predictions #{predictions}",
"average-error: #{mean_square_diff(truth, predictions)}",
... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
procedure dot_product is
type vect is array(Positive range <>) of Integer;
v1 : vect := (1,3,-5);
v2 : vect := (4,-2,-1);
function dotprod(a: vect; b: vect) return Integer is
sum : Integer := 0;
begin
if not (a'Length=b'Length) then raise Constraint_Error; end if;
for p ... |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Erlang | Erlang |
-module( doubly_linked_list ).
-export( [append/2, foreach_next/2, foreach_previous/2, free/1, insert/3, new/1, task/0] ).
append( New, Start ) -> Start ! {append, New}.
foreach_next( Fun, Start ) -> Start ! {foreach_next, Fun}.
foreach_previous( Fun, Start ) -> Start ! {foreach_previous, Fun}.
free( Elemen... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Python | Python | #!/usr/bin/python
def isDisarium(n):
digitos = len(str(n))
suma = 0
x = n
while x != 0:
suma += (x % 10) ** digitos
digitos -= 1
x //= 10
if suma == n:
return True
else:
return False
if __name__ == '__main__':
limite = 19
cont = 0
n = 0
... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #PL.2FM | PL/M | 100H: /* FIND SOME DISARIUM NUMBERS - NUMBERS WHOSE DIGIT POSITION-POWER */
/* SUMS ARE EQUAL TO THE NUMBER, E.G. 135 = 1^1 + 3^2 + 5^3 */
/* CP/M BDOS SYSTEM CALL, IGNORE THE RETURN VALUE */
BDOS: PROCEDURE( FN, ARG ); DECLARE FN BYTE, ARG ADDRESS; GOTO 5; END;
P... |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #REXX | REXX | /*REXX program displays IPV4 and IPV6 addresses for a supplied domain name.*/
parse arg tar . /*obtain optional domain name from C.L.*/
if tar=='' then tar= 'www.kame.net' /*Not specified? Then use the default.*/
tFID = '\TEMP\DNSQUERY.$$$' /*define temp file to store IPV4 outpu... |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Ruby | Ruby | irb(main):001:0> require 'socket'
=> true
irb(main):002:0> Addrinfo.getaddrinfo("www.kame.net", nil, nil, :DGRAM) \
irb(main):003:0* .map! { |ai| ai.ip_address }
=> ["203.178.141.194", "2001:200:dff:fff1:216:3eff:feb1:44d7"] |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Racket | Racket | #lang racket
(require plot)
(define (dragon-turn n)
(if (> (bitwise-and (arithmetic-shift (bitwise-and n (- n)) 1) n) 0)
'L
'R))
(define (rotate heading dir)
(cond
[(eq? dir 'R) (cond [(eq? heading 'N) 'E]
[(eq? heading 'E) 'S]
[(eq? heading 'S) ... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Racket | Racket | #lang racket/base
(require racket/match racket/string)
(define (linear-combination->string es)
(let inr ((es es) (i 1) (rv ""))
(match* (es rv)
[((list) "") "0"]
[((list) rv) rv]
[((list (? zero?) t ...) rv)
(inr t (add1 i) rv)]
[((list n t ...) rv)
(define ±n
(mat... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Raku | Raku | sub linear-combination(@coeff) {
(@coeff Z=> map { "e($_)" }, 1 .. *)
.grep(+*.key)
.map({ .key ~ '*' ~ .value })
.join(' + ')
.subst('+ -', '- ', :g)
.subst(/<|w>1\*/, '', :g)
|| '0'
}
say linear-combination($_) for
[1, 2, 3],
[0, 1, 2, 3],
[1, 0, 3, 4],
[1, 2, 0],
[0, 0, 0],
[0],
[1... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Stata | Stata | prog def hello
di "Hello, World!"
end |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Swift | Swift | /**
Adds two numbers
:param: a an integer.
:param: b another integer.
:returns: the sum of a and b
*/
func add(a: Int, b: Int) -> Int {
return a + b
} |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Tcl | Tcl | #****f* RosettaCode/TclDocDemo
# FUNCTION
# TclDocDemo is a simple illustration of how to do documentation
# of Tcl code using Robodoc.
# SYNOPSYS
# TclDocDemo foo bar
# INPUTS
# foo -- the first part of the message to print
# bar -- the last part of the message to print
# RESULT
# No result
# NOTES
#... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #Scala | Scala | object DiversityPredictionTheorem {
def square(d: Double): Double
= d * d
def average(a: Array[Double]): Double
= a.sum / a.length
def averageSquareDiff(d: Double, predictions: Array[Double]): Double
= average(predictions.map(it => square(it - d)))
def diversityTheorem(truth: Double, predictions: Ar... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Aime | Aime | real
dp(list a, list b)
{
real p, v;
integer i;
p = 0;
for (i, v in a) {
p += v * b[i];
}
p;
}
integer
main(void)
{
o_(dp(list(1r, 3r, -5r), list(4r, -2r, -1r)), "\n");
0;
} |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #F.23 | F# | type DListAux<'T> = {mutable prev: DListAux<'T> option; data: 'T; mutable next: DListAux<'T> option}
type DList<'T> = {mutable front: DListAux<'T> option; mutable back: DListAux<'T> option} //'
let empty() = {front=None; back=None}
let addFront dlist elt =
match dlist.front with
| None ->
let e = Some {pr... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Raku | Raku | my $disarium = (^∞).hyper.map: { $_ if $_ == sum .polymod(10 xx *).reverse Z** 1..* };
put $disarium[^18];
put $disarium[18]; |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Sidef | Sidef | func is_disarium(n) {
n.digits.flip.sum_kv{|k,d| d**(k+1) } == n
}
say 18.by(is_disarium) |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Rust | Rust | use std::net::ToSocketAddrs;
fn main() {
let host = "www.kame.net";
// Ideally, we would want to use std::net::lookup_host to resolve the host ips,
// but at time of writing this, it is still unstable. Fortunately, we can
// still resolve using the ToSocketAddrs trait, but we need to add a port,
/... |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Scala | Scala | import java.net._
InetAddress.getAllByName("www.kame.net").foreach(x => println(x.getHostAddress)) |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Scheme | Scheme | ; Query DNS
(define n (car (hostent:addr-list (gethost "www.kame.net"))))
; Display address as IPv4 and IPv6
(display (inet-ntoa n))(newline)
(display (inet-ntop AF_INET n))(newline)
(display (inet-ntop AF_INET6 n))(newline) |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Raku | Raku | use SVG;
role Lindenmayer {
has %.rules;
method succ {
self.comb.map( { %!rules{$^c} // $c } ).join but Lindenmayer(%!rules)
}
}
my $dragon = "FX" but Lindenmayer( { X => 'X+YF+', Y => '-FX-Y' } );
$dragon++ xx ^15;
my @points = 215, 350;
for $dragon.comb {
state ($x, $y) = @points[0,1];... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #REXX | REXX | /*REXX program displays a finite liner combination in an infinite vector basis. */
@.= .; @.1 = ' 1, 2, 3 ' /*define a specific test case for build*/
@.2 = ' 0, 1, 2, 3 ' /* " " " " " " " */
@.3 = ' 1, 0, 3, 4 ' ... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #Wren | Wren | // The meaning of life!
var mol = 42
// A function to add two numbers
var add = Fn.new { |x, y| x + y }
/* A class with some string utilites */
class StrUtil {
// reverses an ASCII string
static reverse(s) { s[-1..0] }
// capitalizes the first letter of an ASCII string
static capitalize(s) {
... |
http://rosettacode.org/wiki/Documentation | Documentation |
See also
Related task: Comments
Related task: Here_document
| #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 LET a=10: REM a is the number of apples
1000 DEF FN s(q)=q*q: REM s is a function that takes a single numeric parameter and returns its square |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #Sidef | Sidef | func avg_error(m, v) {
v.map { (_ - m)**2 }.sum / v.len
}
func diversity_calc(truth, pred) {
var ae = avg_error(truth, pred)
var cp = pred.sum/pred.len
var ce = (cp - truth)**2
var pd = avg_error(cp, pred)
return [ae, ce, pd]
}
func diversity_format(stats) {
gather {
for t,v in (... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #TypeScript | TypeScript |
function sum(array: Array<number>): number {
return array.reduce((a, b) => a + b)
}
function square(x : number) :number {
return x * x
}
function mean(array: Array<number>): number {
return sum(array) / array.length
}
function averageSquareDiff(a: number, predictions: Array<number>): number {
re... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #ALGOL_68 | ALGOL 68 | MODE DOTFIELD = REAL;
MODE DOTVEC = [1:0]DOTFIELD;
# The "Spread Sheet" way of doing a dot product:
o Assume bounds are equal, and start at 1
o Ignore round off error
#
PRIO SSDOT = 7;
OP SSDOT = (DOTVEC a,b)DOTFIELD: (
DOTFIELD sum := 0;
FOR i TO UPB a DO sum +:= a[i]*b[i] OD;
sum
);
# An improved dot-p... |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Fortran | Fortran |
module dlist
implicit none
type node
type(node), pointer :: next => null()
type(node), pointer :: prev => null()
integer :: data
end type node
type dll
type(node), pointer :: head => null()
type(node), pointer :: tail => null()
integer :: num_nodes = 0
end type dll
public... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #VTL-2 | VTL-2 | 1000 N=1
1010 D=0
1020 :N*10+D)=D
1030 D=D+1
1040 #=D<10*1020
1050 N=2
1060 :N*10)=0
1070 D=1
1080 :N*10+D)=:N-1*10+D)*D
1090 D=D+1
1100 #=D<10*1080
1120 N=N+1
1130 #=N<5*1060
2000 C=0
2010 T=10
2020 L=1
2030 N=0
2040 #=N=T=0*2070
2050 T=T*10
2060 L=L+1
2070 V=N
2080 P=L
2090 S=0
2100 V=V/10
2110 S=S+:P*10+%
2120 P=P-1... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Vlang | Vlang | import strconv
const dmax = 20 // maximum digits
const limit = 20 // maximum number of disariums to find
fn main() {
// Pre-calculated exponential and power serials
mut exp1 := [][]u64{len: 1+dmax, init: []u64{len: 11}}
mut pow1 := [][]u64{len: 1+dmax, init: []u64{len: 11}}
for i := u64(1); i <= ... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #Wren | Wren | import "./math" for Int
var limit = 19
var count = 0
var disarium = []
var n = 0
while (count < limit) {
var sum = 0
var digits = Int.digits(n)
for (i in 0...digits.count) sum = sum + digits[i].pow(i+1)
if (sum == n) {
disarium.add(n)
count = count + 1
}
n = n + 1
}
System.prin... |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "socket.s7i";
const proc: main is func
begin
writeln(numericAddress(inetSocketAddress("www.kame.net", 1024)));
end func; |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Sidef | Sidef | var (err, *res) = Socket.getaddrinfo(
'www.kame.net', 0,
Hash.new(protocol => Socket.IPPROTO_TCP)
);
err && die err;
res.each { |z|
say [Socket.getnameinfo(z{:addr}, Socket.NI_NUMERICHOST)][1];
} |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Standard_ML | Standard ML | - Option.map (NetHostDB.toString o NetHostDB.addr) (NetHostDB.getByName "www.kame.net");
val it = SOME "203.178.141.194": string option |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #RapidQ | RapidQ | DIM angle AS Double
DIM x AS Double, y AS Double
DECLARE SUB PaintCanvas
CREATE form AS QForm
Width = 800
Height = 600
CREATE canvas AS QCanvas
Height = form.ClientHeight
Width = form.ClientWidth
OnPaint = PaintCanvas
END CREATE
END CREATE
SUB turn (degrees AS Double)
... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Ring | Ring |
# Project : Display a linear combination
scalars = [[1, 2, 3], [0, 1, 2, 3], [1, 0, 3, 4], [1, 2, 0], [0, 0, 0], [0], [1, 1, 1], [-1, -1, -1], [-1, -2, 0, -3], [-1]]
for n=1 to len(scalars)
str = ""
for m=1 to len(scalars[n])
scalar = scalars[n] [m]
if scalar != "0"
... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Ruby | Ruby | def linearCombo(c)
sb = ""
c.each_with_index { |n, i|
if n == 0 then
next
end
if n < 0 then
if sb.length == 0 then
op = "-"
else
op = " - "
end
elsif n > 0 then
if sb.length > 0 then
... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Function Square(x As Double) As Double
Return x * x
End Function
Function AverageSquareDiff(a As Double, predictions As IEnumerable(Of Double)) As Double
Return predictions.Select(Function(x) Square(x - a)).Average()
End Function
Sub DiversityTheorem(truth As Dou... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #Wren | Wren | import "/fmt" for Fmt
var averageSquareDiff = Fn.new { |f, preds|
var av = 0
for (pred in preds) av = av + (pred-f)*(pred-f)
return av/preds.count
}
var diversityTheorem = Fn.new { |truth, preds|
var av = (preds.reduce { |sum, pred| sum + pred }) / preds.count
var avErr = averageSquareDiff.call(... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #ALGOL_W | ALGOL W | begin
% computes the dot product of two equal length integer vectors %
% (single dimension arrays ) the length of the vectors must be specified %
% in length. %
integer procedure integerDotProduct( integer array a ( * )
... |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Go | Go | type dlNode struct {
int
next, prev *dlNode
}
// Field 'members' allows loops to be prevented. All nodes
// inserted should be added to members. Code that operates
// on the list can check any pointer against members to
// find out if the pointer is already in the list.
type dlList struct {
members map[... |
http://rosettacode.org/wiki/Disarium_numbers | Disarium numbers | A Disarium number is an integer where the sum of each digit raised to the power of its position in the number, is equal to the number.
E.G.
135 is a Disarium number:
11 + 32 + 53 == 1 + 9 + 125 == 135
There are a finite number of Disarium numbers.
Task
Find and display the first 18 Disarium numbers.
Stretch... | #XPL0 | XPL0 | func Disarium(N); \Return 'true' if N is a Disarium number
int N, N0, D(10), A(10), I, J, Sum;
[N0:= N;
for J:= 0 to 10-1 do A(J):= 1;
I:= 0;
repeat N:= N/10;
D(I):= rem(0);
I:= I+1;
for J:= 0 to I-1 do
A(J):= A(J) * D(J);
until N = 0;
Sum:= 0;
for J:= 0 to I-1 do
Sum:=... |
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #11l | 11l | F mdroot(n)
V count = 0
V mdr = n
L mdr > 9
V m = mdr
V digits_mul = 1
L m != 0
digits_mul *= m % 10
m = m I/ 10
mdr = digits_mul
count++
R (count, mdr)
print(‘Number: (MP, MDR)’)
print(‘====== =========’)
L(n) (123321, 7739, 893, 899998)
print(‘#6: ’.fo... |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Tcl | Tcl | package require udp; # Query by UDP more widely supported, but requires external package
package require dns
set host "www.kame.net"
set v4 [dns::resolve $host -type A]; # Specifically get IPv4 address
set v6 [dns::resolve $host -type AAAA]; # Specifically get IPv6 address
while {[dns::status $v4] eq "connect" ||... |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #VBScript | VBScript |
Function dns_query(url,ver)
Set r = New RegExp
r.Pattern = "Pinging.+?\[(.+?)\].+"
Set objshell = CreateObject("WScript.Shell")
Set objexec = objshell.Exec("%comspec% /c " & "ping -" & ver & " " & url)
WScript.StdOut.WriteLine "URL: " & url
Do Until objexec.StdOut.AtEndOfStream
line = objexec.StdOut.ReadLine
... |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #REXX | REXX | /*REXX program creates & draws an ASCII Dragon Curve (or Harter-Heighway dragon curve).*/
d.= 1; d.L= -d.; @.= ' '; x= 0; x2= x; y= 0; y2= y; z= d.; @.x.y= "∙"
plot_pts = '123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZΘ' /*plot chars*/
loX= 0; hiX= 0; loY= 0; hiY= 0 ... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Rust | Rust |
use std::fmt::{Display, Formatter, Result};
use std::process::exit;
struct Coefficient(usize, f64);
impl Display for Coefficient {
fn fmt(&self, f: &mut Formatter<'_>) -> Result {
let i = self.0;
let c = self.1;
if c == 0. {
return Ok(());
}
write!(
... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Scala | Scala | object LinearCombination extends App {
val combos = Seq(Seq(1, 2, 3), Seq(0, 1, 2, 3),
Seq(1, 0, 3, 4), Seq(1, 2, 0), Seq(0, 0, 0), Seq(0),
Seq(1, 1, 1), Seq(-1, -1, -1), Seq(-1, -2, 0, -3), Seq(-1))
private def linearCombo(c: Seq[Int]): String = {
val sb = new StringBuilder
for {i <- c.indi... |
http://rosettacode.org/wiki/Diversity_prediction_theorem | Diversity prediction theorem | The wisdom of the crowd is the collective opinion of a group of individuals rather than that of a single expert.
Wisdom-of-the-crowds research routinely attributes the superiority of crowd averages over individual judgments to the elimination of individual noise, an explanation that assumes independence of the i... | #zkl | zkl | fcn avgError(m,v){ v.apply('wrap(n){ (n - m).pow(2) }).sum(0.0)/v.len() }
fcn diversityCalc(truth,pred){ //(Float,List of Float)
ae,cp := avgError(truth,pred), pred.sum(0.0)/pred.len();
ce,pd := (cp - truth).pow(2), avgError(cp, pred);
return(ae,ce,pd)
}
fcn diversityFormat(stats){ // ( (averageError,cr... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #APL | APL | 1 3 ¯5 +.× 4 ¯2 ¯1 |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #AppleScript | AppleScript | ----------------------- DOT PRODUCT -----------------------
-- dotProduct :: [Number] -> [Number] -> Number
on dotProduct(xs, ys)
if length of xs = length of ys then
sum(zipWith(my mul, xs, ys))
else
missing value -- arrays of differing dimension
end if
end dotProduct
-----------------... |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Haskell | Haskell | import qualified Data.Map as M
type NodeID = Maybe Rational
data Node a = Node
{vNode :: a,
pNode, nNode :: NodeID}
type DLList a = M.Map Rational (Node a)
empty = M.empty
singleton a = M.singleton 0 $ Node a Nothing Nothing
fcons :: a -> DLList a -> DLList a
fcons a list | M.null list = singleton a
... |
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #Ada | Ada | with Ada.Text_IO, Generic_Root; use Generic_Root;
procedure Multiplicative_Root is
procedure Compute is new Compute_Root("*"); -- "*" for multiplicative roots
package TIO renames Ada.Text_IO;
package NIO is new TIO.Integer_IO(Number);
procedure Print_Numbers(Target_Root: Number; How_Many: Natural)... |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Wren | Wren | /* dns_query.wren */
class Net {
foreign static lookupHost(host)
}
var host = "orange.kame.net"
var addrs = Net.lookupHost(host).split(", ")
System.print(addrs.join("\n")) |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #zkl | zkl | zkl: Network.TCPClientSocket.addrInfo("www.kame.net")
L("orange.kame.net",L("203.178.141.194","2001:200:dff:fff1:216:3eff:feb1:44d7")) |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Ruby | Ruby | Point = Struct.new(:x, :y)
Line = Struct.new(:start, :stop)
Shoes.app(:width => 800, :height => 600, :resizable => false) do
def split_segments(n)
dir = 1
@segments = @segments.inject([]) do |new, l|
a, b, c, d = l.start.x, l.start.y, l.stop.x, l.stop.y
mid_x = a + (c-a)/2.0 - (d-b)/2.0*dir
... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Sidef | Sidef | func linear_combination(coeffs) {
var res = ""
for e,f in (coeffs.kv) {
given(f) {
when (1) {
res += "+e(#{e+1})"
}
when (-1) {
res += "-e(#{e+1})"
}
case (.> 0) {
res += "+#{f}*e(#{e+1})"
... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Arturo | Arturo | dotProduct: function [a,b][
[ensure equal? size a size b]
result: 0
loop 0..(size a)-1 'i [
result: result + a\[i] * b\[i]
]
return result
]
print dotProduct @[1, 3, neg 5] @[4, neg 2, neg 1]
print dotProduct [1 2 3] [4 5 6] |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #Icon_and_Unicon | Icon and Unicon |
class DoubleList (item)
method head ()
node := item
every (node := node.traverse_backwards ()) # move to start of list
return node
end
method tail ()
node := item
every (node := node.traverse_forwards ()) # move to end of list
return node
end
method insert_at_head (value)
h... |
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #ALGOL_68 | ALGOL 68 | BEGIN # Multiplicative Digital Roots #
# structure to hold the results of calculating the digital root & persistence #
MODE DR = STRUCT( INT root, INT persistence );
# returns the product of the digits of number #
OP DIGITPRODU... |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Run_BASIC | Run BASIC | graphic #g, 600,600
RL$ = "R"
loc = 90
pass = 0
[loop]
#g "cls ; home ; north ; down ; fill black"
for i =1 to len(RL$)
v = 255 * i /len(RL$)
#g "color "; v; " 120 "; 255 -v
#g "go "; loc
if mid$(RL$,i,1) ="R" then #g "turn 90" else #g "turn -90"
next i
#g "color 255 120 0"
#g "go "; loc
LR$ =""
for... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Tcl | Tcl | proc lincom {factors} {
set exp 0
set res ""
foreach f $factors {
incr exp
if {$f == 0} {
continue
} elseif {$f == 1} {
append res "+e($exp)"
} elseif {$f == -1} {
append res "-e($exp)"
} elseif {$f > 0} {
append res "+$... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #AutoHotkey | AutoHotkey | Vet1 := "1,3,-5"
Vet2 := "4 , -2 , -1"
MsgBox % DotProduct( Vet1 , Vet2 )
;---------------------------
DotProduct( VectorA , VectorB )
{
Sum := 0
StringSplit, ArrayA, VectorA, `,, %A_Space%
StringSplit, ArrayB, VectorB, `,, %A_Space%
If ( ArrayA0 <> ArrayB0 )
Return ERROR
While ( A_Index <= ArrayA0 )
... |
http://rosettacode.org/wiki/Doubly-linked_list/Definition | Doubly-linked list/Definition | Define the data structure for a complete Doubly Linked List.
The structure should support adding elements to the head, tail and middle of the list.
The structure should not allow circular loops
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definitio... | #J | J | list=: 2 3 5 7 11
|
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #ALGOL_W | ALGOL W | begin
% calculate the Multiplicative Digital Root (mdr) and Multiplicative Persistence (mp) of n %
procedure getMDR ( integer value n
; integer result mdr, mp
) ;
begin
mp := 0;
mdr := abs n;
while mdr > 9 do begin
integer v;
... |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Rust | Rust |
use ggez::{
conf::{WindowMode, WindowSetup},
error::GameResult,
event,
graphics::{clear, draw, present, Color, MeshBuilder},
nalgebra::Point2,
Context,
};
use std::time::Duration;
// L-System to create the sequence needed for a Dragon Curve.
// This function creates the next generation given... |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Visual_Basic_.NET | Visual Basic .NET | Imports System.Text
Module Module1
Function LinearCombo(c As List(Of Integer)) As String
Dim sb As New StringBuilder
For i = 0 To c.Count - 1
Dim n = c(i)
If n < 0 Then
If sb.Length = 0 Then
sb.Append("-")
Else
... |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #AWK | AWK |
# syntax: GAWK -f DOT_PRODUCT.AWK
BEGIN {
v1 = "1,3,-5"
v2 = "4,-2,-1"
if (split(v1,v1arr,",") != split(v2,v2arr,",")) {
print("error: vectors are of unequal lengths")
exit(1)
}
printf("%g\n",dot_product(v1arr,v2arr))
exit(0)
}
function dot_product(v1,v2, i,sum) {
for (i in v1... |
Subsets and Splits
Rosetta Code COBOL Python Hard Tasks
Identifies and retrieves challenging tasks that exist in both COBOL and Python, revealing cross-language programming patterns and difficulty levels for comparative analysis.
Rosetta Code Task Comparisons
Identifies tasks common to both COBOL and Python languages that are described as having difficulty levels, revealing cross-language task similarities and providing useful comparative programming examples.
SQL Code Examples from Training Data
Retrieves raw SQL code examples for the SQL language, which is basic data retrieval without meaningful analysis or patterns.
SQL Code Examples from Training Data
Retrieves raw SQL code examples for the SQL language, which is basic filtering that shows what data looks like but doesn't provide meaningful analysis or patterns.
Select Specific Languages Codes
Retrieves specific programming language names and codes from training data, providing basic filtering but limited analytical value beyond identifying these particular languages.