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<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืืื ื ืืืื ื ืฉืื ืืืืจืื ืืืืก ืขื ืคืื ืงืฆืืืช, ืืื ืื ืงืืจื ืคื?
</p>
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืื ืืืื ืืคืื ืงืฆืืืช ืจืืืืืช, ืงืจืืื ืึพgenerator ืื ืืืืืจื ืขืจื ืืืื.<br>
ืืืงืื ืขืจื ืืื ืืืืืจื ืืขืื ืกืื,... | our_generator = silly_generator() | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืขืงืืืช ืืงืจืืื ืึพ<code>silly_generator</code> ื ืืฆืจ ืื ื ืกืื ืฉืืฆืืืข ืืจืืข ืขื ืืฉืืจื <code>a = 1</code>.<br>
ืืืื ืื ืืืงืฆืืขื ืืกืื ืืื ืืื <dfn>generator iterator</dfn>.
</p>
<img src="images/silly_generator1.png?v=1" width="300px" style="displa... | next_value = next(our_generator)
print(next_value) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืื ืืืืื ืื ืืชืจืืฉ ื ืฆืืจื ืืืืื ืฉื ื ืืืจืื ืืฉืืืื ืฉืงืฉืืจืื ืึพgenerators:<br>
</p>
<ol style="text-align: right; direction: rtl; float: right; clear: both;">
<li>ืงืจืืื ืึพ<code>next</code> ืืื ืืื ืืืืฆื ืขื "ื ืื" (Play) โ ืืื ืืืจืืช ืืกืื ืืจืืฅ ืขื... | print(next(our_generator)) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ื ืกืื ืื ืงืจื ืขื ืขืืฉืื:
</p>
<ol style="text-align: right; direction: rtl; float: right; clear: both;">
<li>ืืืืจื ื ืคืื ืงืฆืื ืืฉื <var>silly_generator</var>, ืฉืืืืจื ืืืืืืจ ืืช ืืขืจืืื <samp>1</samp>, <samp>2</samp> ืึพ<samp dir="ltr">[1, 2, 3]</... | print(next(our_generator)) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืืคื! ืืื ืืื ืืืฆืืคื.<br>
ืืื ืื ืฆืืคื ืื ื ืืขืชืื?<br>
ืืคืขื ืืืื ืฉื ืืงืฉ ืขืจื ืืืคืื ืงืฆืื, ืืกืื ืฉืื ื ืืจืืฅ ืืืื ืืื ืืืชืงื ืึพ<code>yield</code>.<br>
ืืืงืจื ืืื, ื ืงืื ืฉืืืืช <var>StopIteration</var>, ืฉืืืฉืจืช ืื ื ืฉึพ<code>next</code> ืื ืืฆืืื ืื... | print(next(our_generator)) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืืื ืฉืืื ืกืืื ืืืืืืฅ.<br>
ืืืงืจื ืืื ืืคืืื ืื ืืืืืจ ืืืฉืื ืจืข โ ืคืฉืื ืืืืื ื ืืช ืื ืืขืจืืื ืืึพgenerator iterator ืฉืื ื.<br>
ืคืื ืงืฆืืืช ืึพgenerator ืขืืืื ืงืืืืช!<br>
ืืคืฉืจ ืืืฆืืจ ืขืื generator iterator ืื ื ืจืฆื, ืืืงืื ืืช ืื ืืขืจืืื ืฉื ืืฆืืื ืื... | our_generator = silly_generator()
print(next(our_generator))
print(next(our_generator))
print(next(our_generator)) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืื ืืฉืืืฉืืื ืขื ืื, ืื ืงืฆืช ืืืืื.<br>
ืืื ืคืขื ืฉื ืจืฆื ืืืฉืื ืืช ืืขืจื ืืื ื ืฆืืจื ืืจืฉืื <code>next</code>?<br>
ืืืืืช ืืืืืช ืืจื ืืืื ืืืชืจ!
</p>
<span style="text-align: right; direction: rtl; float: right; clear: both;">ืื generator ืืื ืื ... | our_generator = silly_generator()
for item in our_generator:
print(item) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืื ืืชืจืืฉ ืืื?<br>
ืื ืื ื ืืืงืฉืื ืืืืืืช ืึพ<code>for</code> ืืขืืืจ ืขื ืึพgenerator iterator ืฉืื ื.<br>
ืึพ<code>for</code> ืขืืฉื ืขืืืจื ื ืืช ืืขืืืื ืืืืืืืืช:
</p>
<ol style="text-align: right; direction: rtl; float: right; clear: both;">
<... | for item in our_generator:
print(item) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืืืื ื, ืืืืืืช <code>for</code> ืืืืขืืช ืืืคื ืืขืฆืื ืืฉืืืืช <code>StopIteration</code>, ืืืื ืฉืืืื ืฉืืื ืื ืชืงืคืืฅ ืื ื ืืืงืจื ืืื.
</p>
<span style="text-align: right; direction: rtl; float: right; clear: both;">ืืืจืช ืืืคืืกืื</span>
<p style="text-... | our_generator = silly_generator()
items = list(our_generator)
print(items) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืงืื ืฉืืืขืื, ืืฉืชืืฉื ื ืืคืื ืงืฆืื <code>list</code> ืฉืืืืขืช ืืืืืจ ืขืจืืื iterableึพืื ืืจืฉืืืืช.<br>
ืฉืืื ืื ืฉืื ืฉืืืื ื ืื ืืืข ื"ืกืื" ืืืื ืืืื ืืืืื ืื ืืืืจืืช:
</p> | print(list(our_generator)) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<span style="text-align: right; direction: rtl; float: right; clear: both;">ืฉืืืืฉืื ืคืจืงืืืื</span>
<span style="text-align: right; direction: rtl; float: right; clear: both;">ืืืกืืื ืืืืืจืื</span>
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ื ืืชืื ืคืื ืงืฆืื ืจืืืื ืฉืืงืืืช ืืกืคืจ ืฉืื, ืืืืืืจื ืจืฉืื... | def my_range(upper_limit):
numbers = []
current_number = 0
while current_number < upper_limit:
numbers.append(current_number)
current_number = current_number + 1
return numbers
for number in my_range(1000):
print(number) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืคืื ืงืฆืื ืืื ืื ืื ื ืืืฆืจืื ืจืฉืืืช ืืกืคืจืื ืืืฉื, ืืืืืื ืืช ืื ืืืกืคืจืื ืืื 0 ืืืื ืืืกืคืจ ืฉืืืขืืจ ืืคืจืืืจ <var>upper_limit</var>.<br>
ืื ืืฉื ื ืืขืื ืืืืจื โ ืืคืขืืช ืืคืื ืงืฆืื ืืืจืืช ืื ืืฆืื ืืฉืืืื ืจืืื!<br>
ืื ื ืื ืืก ืืืจืืืื ื 1,000 โ ื ืฆืืจื ืืืืืืง ืจืฉืื... | def my_range(upper_limit):
current_number = 0
while current_number < upper_limit:
yield current_number
current_number = current_number + 1
our_generator = my_range(1000)
for number in our_generator:
print(number) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืฉืืื ืื ืืื ืืืจืกื ืืื ืืืื ืืืช ืืืชืจ!<br>
ืืื ืคืขื ืื ืื ื ืคืฉืื ืฉืืืืื ืืช ืขืจืื ืฉื ืืกืคืจ ืืื (<var>current_number</var>) ืืืืฆื.<br>
ืืฉืืืงืฉืื ืืช ืืขืจื ืืื ืืึพgenerator iterator, ืคืื ืงืฆืืืช ืึพgenerator ืืืืจืช ืืขืืื ืืื ืงืืื ืฉืื ืืื ืขืฆืจื:<br>
ืื... | def square_numbers(numbers):
squared_numbers = []
for number in numbers:
squared_numbers.append(number ** 2)
return squared_numbers
for number in square_numbers(my_range(1000)):
print(number) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<span style="text-align: right; direction: rtl; float: right; clear: both;">ืชืฉืืืืช ืืืงืืืช</span>
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืขืืชืื ื ืืืืฅ ืืืฆืข ืืืฉืื ืืจืื, ืฉืืฉืืืชื ืชืืืฉื ืืื ืจื ืืืื.<br>
ืืืงืจื ืืื, ื ืืื ืืืฉืชืืฉ ืึพgenerator ืืื ืืงืื ืืืง ืืืชืืฆืื ืืืื ืืืช,<br>
ืืืื ืฉ... | def find_pythagorean_triples(upper_bound=10_000):
pythagorean_triples = []
for c in range(3, upper_bound):
for b in range(2, c):
for a in range(1, b):
if a ** 2 + b **2 == c ** 2:
pythagorean_triples.append((a, b, c))
return pythagorean_triples
for t... | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<div class="align-center" style="display: flex; text-align: right; direction: rtl;">
<div style="display: flex; width: 10%; float: right; ">
<img src="images/warning.png" style="height: 50px !important;" alt="ืืืืจื!">
</div>
<div style="width: 90%">
<p style="text-align: right; direction: r... | def find_pythagorean_triples(upper_bound=10_000):
for c in range(3, upper_bound):
for b in range(2, c):
for a in range(1, b):
if a ** 2 + b **2 == c ** 2:
yield a, b, c
for triple in find_pythagorean_triples():
print(triple) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืื ืื ืงืจื? ืงืืืื ื ืืช ืืชืฉืืื ืืชืื ืฉืืจืืจ ืฉื ืืื!<br>
ืืืื, ืื ืื ืืืืืง โ ืงืืืื ื ืืืง ืืืชืฉืืืืช. ืฉืืื ืื ืฉืืงืื ืืืฉืื ืืืืคืืก :)<br>
</p>
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืืืืืจืื, ืึพgenerator ืฉืืื ื... | def fibonacci(max_items):
a = 1
b = 1
numbers = [1, 1]
while len(numbers) < max_items:
a, b = b, a + b # Unpacking
numbers.append(b)
return numbers
for number in fibonacci(10):
print(number) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืขืืืช ืืืช, ืึพgenerators ืื ืืืื ืืืืืช ืกืืฃ ืืืืืจ.<br>
ื ืฉืชืืฉ ืึพ<code>while True</code> ืฉืชืืื ืืชืงืืื, ืืื ืฉืืกืืคื ืฉื ืืืจ โ ืชืืื ื ืืืข ืึพ<code>yield</code>:
</p> | def fibonacci():
a = 1
b = 1
numbers = [1, 1]
while True: # ืชืืื ืืชืงืืื
yield a
a, b = b, a + b
generator_iterator = fibonacci()
for number in range(10):
print(next(generator_iterator))
# ืื ื ืืืื ืืืงืฉ ืืงืืืช ืจืื ืืช 10 ืืืืืจืื ืืืืื ืืกืืจื
for number in range(10):
print... | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<div class="align-center" style="display: flex; text-align: right; direction: rtl;">
<div style="display: flex; width: 10%; float: right; ">
<img src="images/warning.png" style="height: 50px !important;" alt="ืืืืจื!">
</div>
<div style="width: 90%">
<p style="text-align: right; direction: r... | def simple_generator():
yield 1
yield 2
yield 3 | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ื ืืฆืืจ ืฉื ื generator iterators ("ืกืื ืื") ืฉืื ืื ืฉืืฆืืืขืื ืืฉืืจื ืืจืืฉืื ื ืฉื ืึพgenerator ืฉืืืคืืข ืืืขืื:
</p> | first_gen = simple_generator()
second_gen = simple_generator() | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืขื ืืื ืื, ืืฉืื ืืืืื ืฉืื ืืื ืืึพgenerator iterators ืืื "ืืฅ" ื ืคืจื ืฉืืฆืืืข ืืฉืืจื ืืจืืฉืื ื ืึพ<var>simple_generator</var>.<br>
ืื ื ืืงืฉ ืืื ืืื ืืื ืืืืืืจ ืขืจื, ื ืงืื ืืฉื ืืื ืืช 1, ืืืืชื ืืฅ ืืืืื ื ืืขืืืจ ืืฉื ื ืึพgenerator iterators ืืืืชืื ืืฉืืจื ืืฉื ... | print(next(first_gen))
print(next(second_gen)) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ื ืืื ืืงืื ืืช <var>first_gen</var>, ืืืืืื, ืืกืืฃ ืืคืื ืงืฆืื:
</p> | print(next(first_gen))
print(next(first_gen)) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
<p style="text-align: right; direction: rtl; float: right; clear: both;">
ืืื <var>second_gen</var> ืืื ืืฅ ื ืคืจื, ืฉืขืืืื ืืฆืืืข ืืฉืืจื ืืฉื ืืื ืฉื ืคืื ืงืฆืืืช ืึพgenerator.<br>
ืื ื ืืงืฉ ืืื ื ืืช ืืขืจื ืืื, ืืื ืืืฉืื ืืช ืืืกืข ืืืขืจื <samp>2</samp>:<br>
</p> | print(next(second_gen)) | week05/3_Generators.ipynb | PythonFreeCourse/Notebooks | mit |
Getting the data
Here you can download the SVHN dataset. Run the cell above and it'll download to your machine. | from urllib.request import urlretrieve
from os.path import isfile, isdir
from tqdm import tqdm
data_dir = 'data/'
if not isdir(data_dir):
raise Exception("Data directory doesn't exist!")
class DLProgress(tqdm):
last_block = 0
def hook(self, block_num=1, block_size=1, total_size=None):
self.total... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
These SVHN files are .mat files typically used with Matlab. However, we can load them in with scipy.io.loadmat which we imported above. | trainset = loadmat(data_dir + 'train_32x32.mat')
testset = loadmat(data_dir + 'test_32x32.mat') | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Here I'm showing a small sample of the images. Each of these is 32x32 with 3 color channels (RGB). These are the real images we'll pass to the discriminator and what the generator will eventually fake. | idx = np.random.randint(0, trainset['X'].shape[3], size=36)
fig, axes = plt.subplots(6, 6, sharex=True, sharey=True, figsize=(5,5),)
for ii, ax in zip(idx, axes.flatten()):
ax.imshow(trainset['X'][:,:,:,ii], aspect='equal')
ax.xaxis.set_visible(False)
ax.yaxis.set_visible(False)
plt.subplots_adjust(wspace=0... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Here we need to do a bit of preprocessing and getting the images into a form where we can pass batches to the network. First off, we need to rescale the images to a range of -1 to 1, since the output of our generator is also in that range. We also have a set of test and validation images which could be used if we're tr... | def scale(x, feature_range=(-1, 1)):
# scale to (0, 1)
x = ((x - x.min())/(255 - x.min()))
# scale to feature_range
min, max = feature_range
x = x * (max - min) + min
return x
class Dataset:
def __init__(self, train, test, val_frac=0.5, shuffle=False, scale_func=None):
split_id... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Network Inputs
Here, just creating some placeholders like normal. | def model_inputs(real_dim, z_dim):
inputs_real = tf.placeholder(tf.float32, (None, *real_dim), name='input_real')
inputs_z = tf.placeholder(tf.float32, (None, z_dim), name='input_z')
return inputs_real, inputs_z | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Generator
Here you'll build the generator network. The input will be our noise vector z as before. Also as before, the output will be a $tanh$ output, but this time with size 32x32 which is the size of our SVHN images.
What's new here is we'll use convolutional layers to create our new images. The first layer is a full... | def generator(z, output_dim, reuse=False, alpha=0.2, training=True):
with tf.variable_scope('generator', reuse=reuse):
# First fully connected layer
x
# Output layer, 32x32x3
logits =
out = tf.tanh(logits)
return out | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Discriminator
Here you'll build the discriminator. This is basically just a convolutional classifier like you've build before. The input to the discriminator are 32x32x3 tensors/images. You'll want a few convolutional layers, then a fully connected layer for the output. As before, we want a sigmoid output, and you'll n... | def discriminator(x, reuse=False, alpha=0.2):
with tf.variable_scope('discriminator', reuse=reuse):
# Input layer is 32x32x3
x =
logits =
out =
return out, logits | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Model Loss
Calculating the loss like before, nothing new here. | def model_loss(input_real, input_z, output_dim, alpha=0.2):
"""
Get the loss for the discriminator and generator
:param input_real: Images from the real dataset
:param input_z: Z input
:param out_channel_dim: The number of channels in the output image
:return: A tuple of (discriminator loss, gen... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Optimizers
Not much new here, but notice how the train operations are wrapped in a with tf.control_dependencies block so the batch normalization layers can update their population statistics. | def model_opt(d_loss, g_loss, learning_rate, beta1):
"""
Get optimization operations
:param d_loss: Discriminator loss Tensor
:param g_loss: Generator loss Tensor
:param learning_rate: Learning Rate Placeholder
:param beta1: The exponential decay rate for the 1st moment in the optimizer
:ret... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Building the model
Here we can use the functions we defined about to build the model as a class. This will make it easier to move the network around in our code since the nodes and operations in the graph are packaged in one object. | class GAN:
def __init__(self, real_size, z_size, learning_rate, alpha=0.2, beta1=0.5):
tf.reset_default_graph()
self.input_real, self.input_z = model_inputs(real_size, z_size)
self.d_loss, self.g_loss = model_loss(self.input_real, self.input_z,
... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Here is a function for displaying generated images. | def view_samples(epoch, samples, nrows, ncols, figsize=(5,5)):
fig, axes = plt.subplots(figsize=figsize, nrows=nrows, ncols=ncols,
sharey=True, sharex=True)
for ax, img in zip(axes.flatten(), samples[epoch]):
ax.axis('off')
img = ((img - img.min())*255 / (img.max() ... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
And another function we can use to train our network. Notice when we call generator to create the samples to display, we set training to False. That's so the batch normalization layers will use the population statistics rather than the batch statistics. Also notice that we set the net.input_real placeholder when we run... | def train(net, dataset, epochs, batch_size, print_every=10, show_every=100, figsize=(5,5)):
saver = tf.train.Saver()
sample_z = np.random.uniform(-1, 1, size=(72, z_size))
samples, losses = [], []
steps = 0
with tf.Session() as sess:
sess.run(tf.global_variables_initializer())
for ... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Hyperparameters
GANs are very senstive to hyperparameters. A lot of experimentation goes into finding the best hyperparameters such that the generator and discriminator don't overpower each other. Try out your own hyperparameters or read the DCGAN paper to see what worked for them.
Exercise: Find hyperparameters to tr... | real_size = (32,32,3)
z_size = 100
learning_rate = 0.001
batch_size = 64
epochs = 1
alpha = 0.01
beta1 = 0.9
# Create the network
net = GAN(real_size, z_size, learning_rate, alpha=alpha, beta1=beta1)
# Load the data and train the network here
dataset = Dataset(trainset, testset)
losses, samples = train(net, dataset, ... | dcgan-svhn/DCGAN_Exercises.ipynb | kitu2007/dl_class | mit |
Setting up the Code
Before we can plot our Dirichlet distributions, we need to do three things:
Generate a set of x-y coordinates over our equilateral triangle
Map the x-y coordinates to the 2-simplex coordinate space
Compute Dir(ฮฑ)Dir(ฮฑ) for each point | def xy2bc(xy, tol=1.e-3):
'''Converts 2D Cartesian coordinates to barycentric.'''
s = [(corners[i] - midpoints[i]).dot(xy - midpoints[i]) / 0.75 for i in range(3)]
return np.clip(s, tol, 1.0 - tol) | examples/python/Dirichlet distribution.ipynb | iaja/scalaLDAvis | apache-2.0 |
Gamma: $\Gamma \left( z \right) = \int\limits_0^\infty {x^{z - 1} e^{ - x} dx}$
$
\text{Dir}\left(\boldsymbol{\alpha}\right)\rightarrow \mathrm{p}\left(\boldsymbol{\theta}\mid\boldsymbol{\alpha}\right)=\frac{\Gamma\left(\sum_{i=1}^{k}\boldsymbol{\alpha}{i}\right)}{\prod{i=1}^{k}\Gamma\left(\boldsymbol{\alpha}{i}\right)... | class Dirichlet(object):
def __init__(self, alpha):
self._alpha = np.array(alpha)
self._coef = gamma(np.sum(self._alpha)) / reduce(mul, [gamma(a) for a in self._alpha])
def pdf(self, x):
'''Returns pdf value for `x`.'''
return self._coef * reduce(mul, [xx ** (aa - 1) for (xx, aa)... | examples/python/Dirichlet distribution.ipynb | iaja/scalaLDAvis | apache-2.0 |
Download and Explore the Data |
#downloading dataset
!wget -nv -O ../data/PierceCricketData.csv https://ibm.box.com/shared/static/fjbsu8qbwm1n5zsw90q6xzfo4ptlsw96.csv
df = pd.read_csv("../data/PierceCricketData.csv")
df.head() | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
<h6> Plot the Data Points </h6> |
%matplotlib inline
x_data, y_data = (df["Chirps"].values,df["Temp"].values)
# plots the data points
plt.plot(x_data, y_data, 'ro')
# label the axis
plt.xlabel("# Chirps per 15 sec")
plt.ylabel("Temp in Farenhiet")
| dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
Looking at the scatter plot we can analyse that there is a linear relationship between the data points that connect chirps to the temperature and optimal way to infer this knowledge is by fitting a line that best describes the data. Which follows the linear equation:
#### Ypred... | # Create place holders and Variables along with the Linear model.
m = tf.Variable(3, dtype=tf.float32)
c = tf.Variable(2, dtype=tf.float32)
x = tf.placeholder(dtype=tf.float32, shape=x_data.size)
y = tf.placeholder(dtype=tf.float32, shape=y_data.size)
# Linear model
y_pred = m * x + c | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
<div align="right">
<a href="#createvar" class="btn btn-default" data-toggle="collapse">Click here for the solution</a>
</div>
<div id="createvar" class="collapse">
```
X = tf.placeholder(tf.float32, shape=(x_data.size))
Y = tf.placeholder(tf.float32,shape=(y_data.size))
# tf.Variable call creates a single updatable... | #create session and initialize variables
session = tf.Session()
session.run(tf.global_variables_initializer())
#get prediction with initial parameter values
y_vals = session.run(y_pred, feed_dict={x: x_data})
#Your code goes here
plt.plot(x_data, y_vals, label='Predicted')
plt.scatter(x_data, y_data, color='red', lab... | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
<div align="right">
<a href="#matmul1" class="btn btn-default" data-toggle="collapse">Click here for the solution</a>
</div>
<div id="matmul1" class="collapse">
```
pred = session.run(Ypred, feed_dict={X:x_data})
#plot initial prediction against datapoints
plt.plot(x_data, pred)
plt.plot(x_data, y_data, 'ro')
# label... | loss = tf.reduce_mean(tf.squared_difference(y_pred*0.1, y*0.1)) | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
<div align="right">
<a href="#matmul12" class="btn btn-default" data-toggle="collapse">Click here for the solution</a>
</div>
<div id="matmul12" class="collapse">
```
# normalization factor
nf = 1e-1
# seting up the loss function
loss = tf.reduce_mean(tf.squared_difference(Ypred*nf,Y*nf))
```
</div>
Define an Optimiza... | # Your code goes here
optimizer = tf.train.GradientDescentOptimizer(0.01)
train_op = optimizer.minimize(loss) | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
<div align="right">
<a href="#matmul13" class="btn btn-default" data-toggle="collapse">Click here for the solution</a>
</div>
<div id="matmul13" class="collapse">
```
optimizer = tf.train.GradientDescentOptimizer(learning_rate=0.01)
#optimizer = tf.train.AdagradOptimizer(0.01 )
# pass the loss function that optimizer ... | session.run(tf.global_variables_initializer()) | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
Run session to train and predict the values of 'm' and 'c' for different training steps along with storing the losses in each step
Get the predicted m and c values by running a session on Training a linear model. Also collect the loss for different steps to print and plot. | convergenceTolerance = 0.0001
previous_m = np.inf
previous_c = np.inf
steps = {}
steps['m'] = []
steps['c'] = []
losses=[]
for k in range(10000):
########## Your Code goes Here ###########
_, _l, _m, _c = session.run([train_op, loss, m, c], feed_dict={x: x_data, y: y_data})
steps['m'].append(_m)
ste... | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
<div align="right">
<a href="#matmul18" class="btn btn-default" data-toggle="collapse">Click here for the solution</a>
</div>
<div id="matmul18" class="collapse">
```
# run a session to train , get m and c values with loss function
_, _m , _c,_l = session.run([train, m, c,loss],feed_dict={X:x_data,Y:y_data})
```
</d... | # Your Code Goes Here
plt.plot(losses) | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
<div align="right">
<a href="#matmul199" class="btn btn-default" data-toggle="collapse">Click here for the solution</a>
</div>
<div id="matmul199" class="collapse">
```
plt.plot(losses[:])
```
</div> | y_vals_pred = y_pred.eval(session=session, feed_dict={x: x_data})
plt.scatter(x_data, y_vals_pred, marker='x', color='blue', label='Predicted')
plt.scatter(x_data, y_data, label='GT', color='red')
plt.legend()
plt.ylabel('Temperature (Fahrenheit)')
plt.xlabel('# Chirps per 15 s')
session.close() | dl_tf_BDU/1.Intro_TF/ML0120EN-1.2-Exercise-LinearRegression.ipynb | santipuch590/deeplearning-tf | mit |
Efficient serving
<table class="tfo-notebook-buttons" align="left">
<td>
<a target="_blank" href="https://www.tensorflow.org/recommenders/examples/efficient_serving"><img src="https://www.tensorflow.org/images/tf_logo_32px.png" />View on TensorFlow.org</a>
</td>
<td>
<a target="_blank" href="https://colab... | !pip install -q tensorflow-recommenders
!pip install -q --upgrade tensorflow-datasets | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
We also need to install scann: it's an optional dependency of TFRS, and so needs to be installed separately. | !pip install -q scann | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Set up all the necessary imports. | from typing import Dict, Text
import os
import pprint
import tempfile
import numpy as np
import tensorflow as tf
import tensorflow_datasets as tfds
import tensorflow_recommenders as tfrs | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
And load the data: | # Load the MovieLens 100K data.
ratings = tfds.load(
"movielens/100k-ratings",
split="train"
)
# Get the ratings data.
ratings = (ratings
# Retain only the fields we need.
.map(lambda x: {"user_id": x["user_id"], "movie_title": x["movie_title"]})
# Cache for efficiency.
... | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Before we can build a model, we need to set up the user and movie vocabularies: | user_ids = ratings.map(lambda x: x["user_id"])
unique_movie_titles = np.unique(np.concatenate(list(movies.batch(1000))))
unique_user_ids = np.unique(np.concatenate(list(user_ids.batch(1000)))) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
We'll also set up the training and test sets: | tf.random.set_seed(42)
shuffled = ratings.shuffle(100_000, seed=42, reshuffle_each_iteration=False)
train = shuffled.take(80_000)
test = shuffled.skip(80_000).take(20_000) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Model definition
Just as in the basic retrieval tutorial, we build a simple two-tower model. | class MovielensModel(tfrs.Model):
def __init__(self):
super().__init__()
embedding_dimension = 32
# Set up a model for representing movies.
self.movie_model = tf.keras.Sequential([
tf.keras.layers.StringLookup(
vocabulary=unique_movie_titles, mask_token=None),
# We add an additi... | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Fitting and evaluation
A TFRS model is just a Keras model. We can compile it: | model = MovielensModel()
model.compile(optimizer=tf.keras.optimizers.Adagrad(learning_rate=0.1)) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Estimate it: | model.fit(train.batch(8192), epochs=3) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
And evaluate it. | model.evaluate(test.batch(8192), return_dict=True) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Approximate prediction
The most straightforward way of retrieving top candidates in response to a query is to do it via brute force: compute user-movie scores for all possible movies, sort them, and pick a couple of top recommendations.
In TFRS, this is accomplished via the BruteForce layer: | brute_force = tfrs.layers.factorized_top_k.BruteForce(model.user_model)
brute_force.index_from_dataset(
movies.batch(128).map(lambda title: (title, model.movie_model(title)))
) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Once created and populated with candidates (via the index method), we can call it to get predictions out: | # Get predictions for user 42.
_, titles = brute_force(np.array(["42"]), k=3)
print(f"Top recommendations: {titles[0]}") | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
On a small dataset of under 1000 movies, this is very fast: | %timeit _, titles = brute_force(np.array(["42"]), k=3) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
But what happens if we have more candidates - millions instead of thousands?
We can simulate this by indexing all of our movies multiple times: | # Construct a dataset of movies that's 1,000 times larger. We
# do this by adding several million dummy movie titles to the dataset.
lots_of_movies = tf.data.Dataset.concatenate(
movies.batch(4096),
movies.batch(4096).repeat(1_000).map(lambda x: tf.zeros_like(x))
)
# We also add lots of dummy embeddings by ra... | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
We can build a BruteForce index on this larger dataset: | brute_force_lots = tfrs.layers.factorized_top_k.BruteForce()
brute_force_lots.index_from_dataset(
tf.data.Dataset.zip((lots_of_movies, lots_of_movies_embeddings))
) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
The recommendations are still the same | _, titles = brute_force_lots(model.user_model(np.array(["42"])), k=3)
print(f"Top recommendations: {titles[0]}") | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
But they take much longer. With a candidate set of 1 million movies, brute force prediction becomes quite slow: | %timeit _, titles = brute_force_lots(model.user_model(np.array(["42"])), k=3) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
As the number of candidate grows, the amount of time needed grows linearly: with 10 million candidates, serving top candidates would take 250 milliseconds. This is clearly too slow for a live service.
This is where approximate mechanisms come in.
Using ScaNN in TFRS is accomplished via the tfrs.layers.factorized_top_k.... | scann = tfrs.layers.factorized_top_k.ScaNN(num_reordering_candidates=100)
scann.index_from_dataset(
tf.data.Dataset.zip((lots_of_movies, lots_of_movies_embeddings))
) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
The recommendations are (approximately!) the same | _, titles = scann(model.user_model(np.array(["42"])), k=3)
print(f"Top recommendations: {titles[0]}") | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
But they are much, much faster to compute: | %timeit _, titles = scann(model.user_model(np.array(["42"])), k=3) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
In this case, we can retrieve the top 3 movies out of a set of ~1 million in around 2 milliseconds: 15 times faster than by computing the best candidates via brute force. The advantage of approximate methods grows even larger for larger datasets.
Evaluating the approximation
When using approximate top K retrieval mecha... | # Override the existing streaming candidate source.
model.task.factorized_metrics = tfrs.metrics.FactorizedTopK(
candidates=lots_of_movies_embeddings
)
# Need to recompile the model for the changes to take effect.
model.compile()
%time baseline_result = model.evaluate(test.batch(8192), return_dict=True, verbose=Fa... | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
We can do the same using ScaNN: | model.task.factorized_metrics = tfrs.metrics.FactorizedTopK(
candidates=scann
)
model.compile()
# We can use a much bigger batch size here because ScaNN evaluation
# is more memory efficient.
%time scann_result = model.evaluate(test.batch(8192), return_dict=True, verbose=False) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
ScaNN based evaluation is much, much quicker: it's over ten times faster! This advantage is going to grow even larger for bigger datasets, and so for large datasets it may be prudent to always run ScaNN-based evaluation to improve model development velocity.
But how about the results? Fortunately, in this case the resu... | print(f"Brute force top-100 accuracy: {baseline_result['factorized_top_k/top_100_categorical_accuracy']:.2f}")
print(f"ScaNN top-100 accuracy: {scann_result['factorized_top_k/top_100_categorical_accuracy']:.2f}") | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
This suggests that on this artificial datase, there is little loss from the approximation. In general, all approximate methods exhibit speed-accuracy tradeoffs. To understand this in more depth you can check out Erik Bernhardsson's ANN benchmarks.
Deploying the approximate model
The ScaNN-based model is fully integrat... | lots_of_movies_embeddings
# We re-index the ScaNN layer to include the user embeddings in the same model.
# This way we can give the saved model raw features and get valid predictions
# back.
scann = tfrs.layers.factorized_top_k.ScaNN(model.user_model, num_reordering_candidates=1000)
scann.index_from_dataset(
tf.d... | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
and then load it and serve, getting exactly the same results back: | _, titles = loaded(tf.constant(["42"]))
print(f"Top recommendations: {titles[0][:3]}") | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
The resulting model can be served in any Python service that has TensorFlow and ScaNN installed.
It can also be served using a customized version of TensorFlow Serving, available as a Docker container on Docker Hub. You can also build the image yourself from the Dockerfile.
Tuning ScaNN
Now let's look into tuning our S... | # Process queries in groups of 1000; processing them all at once with brute force
# may lead to out-of-memory errors, because processing a batch of q queries against
# a size-n dataset takes O(nq) space with brute force.
titles_ground_truth = tf.concat([
brute_force_lots(queries, k=10)[1] for queries in
test.batch(... | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Our variable titles_ground_truth now contains the top-10 movie recommendations returned by brute-force retrieval. Now we can compute the same recommendations when using ScaNN: | # Get all user_id's as a 1d tensor of strings
test_flat = np.concatenate(list(test.map(lambda x: x["user_id"]).batch(1000).as_numpy_iterator()), axis=0)
# ScaNN is much more memory efficient and has no problem processing the whole
# batch of 20000 queries at once.
_, titles = scann(test_flat, k=10) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Next, we define our function that computes recall. For each query, it counts how many results are in the intersection of the brute force and the ScaNN results and divides this by the number of brute force results. The average of this quantity over all queries is our recall. | def compute_recall(ground_truth, approx_results):
return np.mean([
len(np.intersect1d(truth, approx)) / len(truth)
for truth, approx in zip(ground_truth, approx_results)
]) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
This gives us baseline recall@10 with the current ScaNN config: | print(f"Recall: {compute_recall(titles_ground_truth, titles):.3f}") | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
We can also measure the baseline latency: | %timeit -n 1000 scann(np.array(["42"]), k=10) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
Let's see if we can do better!
To do this, we need a model of how ScaNN's tuning knobs affect performance. Our current model uses ScaNN's tree-AH algorithm. This algorithm partitions the database of embeddings (the "tree") and then scores the most promising of these partitions using AH, which is a highly optimized appr... | scann2 = tfrs.layers.factorized_top_k.ScaNN(
model.user_model,
num_leaves=1000,
num_leaves_to_search=100,
num_reordering_candidates=1000)
scann2.index_from_dataset(
tf.data.Dataset.zip((lots_of_movies, lots_of_movies_embeddings))
)
_, titles2 = scann2(test_flat, k=10)
print(f"Recall: {compute_rec... | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
However, as a tradeoff, our latency has also increased. This is because the partitioning step has gotten more expensive; scann picks the top 10 of 100 partitions while scann2 picks the top 100 of 1000 partitions. The latter can be more expensive because it involves looking at 10 times as many partitions. | %timeit -n 1000 scann2(np.array(["42"]), k=10) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
In general, tuning ScaNN search is about picking the right tradeoffs. Each individual parameter change generally won't make search both faster and more accurate; our goal is to tune the parameters to optimally trade off between these two conflicting goals.
In our case, scann2 significantly improved recall over scann at... | scann3 = tfrs.layers.factorized_top_k.ScaNN(
model.user_model,
num_leaves=1000,
num_leaves_to_search=70,
num_reordering_candidates=400)
scann3.index_from_dataset(
tf.data.Dataset.zip((lots_of_movies, lots_of_movies_embeddings))
)
_, titles3 = scann3(test_flat, k=10)
print(f"Recall: {compute_recall(... | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
scann3 delivers about a 3% absolute recall gain over scann while also delivering lower latency: | %timeit -n 1000 scann3(np.array(["42"]), k=10) | docs/examples/efficient_serving.ipynb | tensorflow/recommenders | apache-2.0 |
ๅคๆฐๅใจใใผใฟใฎๅ
ๅฎนใกใข
CENSUS: ๅธๅบ็บๆใณใผใ(9ๆก)
P: ๆ็ดไพกๆ ผ
S: ๅฐๆ้ข็ฉ
L: ๅๅฐ้ข็ฉ
R: ้จๅฑๆฐ
RW: ๅ้ข้่ทฏๅน
ๅก
CY: ๅปบ็ฏๅนด
A: ๅปบ็ฏๅพๅนดๆฐ(ๆ็ดๆ)
TS: ๆๅฏ้ง
ใพใงใฎ่ท้ข
TT: ๆฑไบฌ้ง
ใพใงใฎๆ้
ACC: ใฟใผใใใซ้ง
ใพใงใฎๆ้
WOOD: ๆจ้ ใใใผ
SOUTH: ๅๅใใใใผ
RSD: ไฝๅฑ
็ณปๅฐๅใใใผ
CMD: ๅๆฅญ็ณปๅฐๅใใใผ
IDD: ๅทฅๆฅญ็ณปๅฐๅใใใผ
FAR: ๅปบใบใ็
FLR: ๅฎน็ฉ็
TDQ: ๆ็ดๆ็น(ๅๅๆ)
X: ็ทฏๅบฆ
Y:... | data = pd.read_csv("TokyoSingle.csv")
data = data.dropna()
CITY_NAME = data['CITY_CODE'].copy()
CITY_NAME[CITY_NAME == 13101] = '01ๅไปฃ็ฐๅบ'
CITY_NAME[CITY_NAME == 13102] = "02ไธญๅคฎๅบ"
CITY_NAME[CITY_NAME == 13103] = "03ๆธฏๅบ"
CITY_NAME[CITY_NAME == 13104] = "04ๆฐๅฎฟๅบ"
CITY_NAME[CITY_NAME == 13105] = "05ๆไบฌๅบ"
CITY_NAME[CITY_NAME == ... | ไธๅ็ฃ/model2_1.ipynb | NlGG/Projects | mit |
ๅธๅบ็บๆๅฅใฎไปถๆฐใ้่จ | print(data['CITY_NAME'].value_counts())
vars = ['P', 'S', 'L', 'R', 'RW', 'A', 'TS', 'TT', 'WOOD', 'SOUTH', 'CMD', 'IDD', 'FAR', 'X', 'Y']
eq = fml_build(vars)
y, X = dmatrices(eq, data=data, return_type='dataframe')
CITY_NAME = pd.get_dummies(data['CITY_NAME'])
TDQ = pd.get_dummies(data['TDQ'... | ไธๅ็ฃ/model2_1.ipynb | NlGG/Projects | mit |
้ใOLSใฎ่ชคๅทฎใ็ทใOLSใจๆทฑๅฑคๅญฆ็ฟใ็ตใฟๅใใใ่ชคๅทฎใ | model.compare()
print(np.mean(model.error1))
print(np.mean(model.error2))
print(np.mean(np.abs(model.error1)))
print(np.mean(np.abs(model.error2)))
print(max(np.abs(model.error1)))
print(max(np.abs(model.error2)))
print(np.var(model.error1))
print(np.var(model.error2))
fig = plt.figure()
ax = fig.add_subplot(111)
... | ไธๅ็ฃ/model2_1.ipynb | NlGG/Projects | mit |
Sawtooth map
Let's examine simple system where each next element is derived by previous element by the following rule:
$$x_{n+1}={2 x_n}$$
where operator ${}$ means taking decimal part of a number. | #from math import trunc
assert trunc(1.5) == 1.0
assert trunc(12.59) == 12.0
assert trunc(1) == 1.0
sawtooth = lambda x: round(2*x-trunc(2*x),8)
sawtooth_borders = [pd.DataFrame([(0,0),(0.5,1)]), pd.DataFrame([(0.5,0),(1,1)])]
for x0 in [0.4, 0.41, 0.42, 0.43]:
cobweb_plot(take(iterator(sawtooth, x0=x0), n=30, sk... | Dynamical chaos.ipynb | schmooser/physics | mit |
Logistic map
Here we have very simple equation:
$$x_{n+1} = k x_n (1 - x_n)$$
where $k$ is some fixed constant. | logistic = lambda k, x: k*x*(1-x)
limits = [0,1]
for k in [2.8, 3.2, 3.5, 3.9]:
l = lambda x: logistic(k, x)
cobweb_plot(take(iterator(l, x0=0.1), n=30, skip=500), limits, 'plot', boundary(l, limits))
# let's plot the bifurcation diagram
dots = []
for k in linspace(2.5, 4, 0.001):
for dot in set(take(ite... | Dynamical chaos.ipynb | schmooser/physics | mit |
Define A Function, f(x) | # Define a function that,
def f(x):
# Outputs x multiplied by a random number drawn from a normal distribution
return x * np.random.normal(size=1)[0] | mathematics/argmin_and_argmax.ipynb | tpin3694/tpin3694.github.io | mit |
Create Some Values Of x | # Create some values of x
xs = [1,2,3,4,5,6] | mathematics/argmin_and_argmax.ipynb | tpin3694/tpin3694.github.io | mit |
Find The Argmin Of f(x) | #Define argmin that
def argmin(f, xs):
# Applies f on all the x's
data = [f(x) for x in xs]
# Finds index of the smallest output of f(x)
index_of_min = data.index(min(data))
# Returns the x that produced that output
return xs[index_of_min]
# Run the argmin function
argmin(f, xs) | mathematics/argmin_and_argmax.ipynb | tpin3694/tpin3694.github.io | mit |
Check Our Results | print('x','|', 'f(x)')
print('--------------')
for x in xs:
print(x,'|', f(x)) | mathematics/argmin_and_argmax.ipynb | tpin3694/tpin3694.github.io | mit |
We use experimental absorption coefficients of crystalline silicon and assume that the absorptivity follows Beer-Lambert's law. Also, we assume that every abosorped photons can be converted into electrons. In this case, having a 100% reflector on the back side of silicon can be thought of as doubling the thickness of s... | %matplotlib inline
from pypvcell.photocurrent import conv_abs_to_qe,calc_jsc
from pypvcell.illumination import Illumination
from pypvcell.spectrum import Spectrum
import numpy as np
import matplotlib.pyplot as plt
abs_file = "/Users/kanhua/Dropbox/Programming/pypvcell/legacy/si_alpha.csv"
si_alpha = np.loadtxt(abs_f... | legacy/Enhancement in Jsc of back reflector.ipynb | kanhua/pypvcell | apache-2.0 |
Photocurrent with and without the back reflector | plt.semilogx(layer_t*1e6, jsc_baseline,hold=True,label="Si")
plt.semilogx(layer_t*1e6,jsc_full_r,label="Si+100% mirror")
plt.xlabel("thickness of Si substrate (um)")
plt.ylabel("Jsc (A/m^2)")
plt.legend(loc="best") | legacy/Enhancement in Jsc of back reflector.ipynb | kanhua/pypvcell | apache-2.0 |
Normlize the Jsc(Si+mirror) by Jsc(Si only) | plt.semilogx(layer_t*1e6,jsc_full_r/jsc_baseline)
plt.xlabel("thickness of Si substrate (um)")
plt.ylabel("Normalized Jsc enhancement")
plt.savefig("jsc_enhancement.pdf")
plt.show() | legacy/Enhancement in Jsc of back reflector.ipynb | kanhua/pypvcell | apache-2.0 |
We can see that the back reflector can be very effective when the thickness of silicon substrate is thin (< 1um). Silicon substrates with more than 10-um thicknesses cannot be benefited from this structure very well. This is the reason that photonic or plasmonic structure are useful for thin-film or ultra-thin-film sil... | # more detailed investigation
plt.semilogx(layer_t*1e6,jsc_full_r/jsc_baseline)
plt.xlabel("thickness of Si substrate (um)")
plt.ylabel("Jsc enhancement (2x)")
plt.xlim([100,1000])
plt.ylim([1.0,1.5])
plt.show() | legacy/Enhancement in Jsc of back reflector.ipynb | kanhua/pypvcell | apache-2.0 |
More audacious assumption
Assume that somehow we have a novel reflector that can increase the optical absorption length by 10 times. | while not it.finished:
t=it[0] #thickness of Si layer
qe=conv_abs_to_qe(si_alpha_sp,t)
jsc_baseline[it.index]=calc_jsc(Illumination("AM1.5g"), qe)
# Assme 100% reflection on the back side, essentially doubling the thickness of silicon
qe_full_r=conv_abs_to_qe(si_alpha_sp,t*10)
jsc_full_r[it.i... | legacy/Enhancement in Jsc of back reflector.ipynb | kanhua/pypvcell | apache-2.0 |
repo_path is the path to a clone of swcarpentry/make-novice | repo_path = os.path.join(
home,
'Dropbox/spikes/make-novice',
)
assert os.path.exists(repo_path) | content/posts/makefile-tutorial/makefile_tutorial_0.ipynb | dm-wyncode/zipped-code | mit |
paths are the paths to child directories in a clone of swcarpentry/make-novice | paths = (
'code',
'data',
)
paths = (
code,
data,
) = [os.path.join(repo_path, path) for path in paths]
assert all(os.path.exists(path) for path in paths) | content/posts/makefile-tutorial/makefile_tutorial_0.ipynb | dm-wyncode/zipped-code | mit |
Begin tutorial.
Use the magic run to execute the Python script wordcount.py.
The variables with '$' in front of them are the values of the Python variables in this
notebook. | run $code/wordcount.py $data/books/isles.txt $repo_path/isles.dat | content/posts/makefile-tutorial/makefile_tutorial_0.ipynb | dm-wyncode/zipped-code | mit |
Use shell to examine the first 5 lines of the output file from running wordcount.py | !head -5 $repo_path/isles.dat | content/posts/makefile-tutorial/makefile_tutorial_0.ipynb | dm-wyncode/zipped-code | mit |
We can see that the file consists of one row per word. Each row shows the word itself, the number of occurrences of that word, and the number of occurrences as a percentage of the total number of words in the text file. | run $code/wordcount.py $data/books/abyss.txt $repo_path/abyss.dat
!head -5 $repo_path/abyss.dat | content/posts/makefile-tutorial/makefile_tutorial_0.ipynb | dm-wyncode/zipped-code | mit |
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