import numpy as np class SparseMatrix(): def __init__(self,triple): self.matrix_user = {} self.matrix_item = {} for item in triple: if item[0] not in self.matrix_user: self.matrix_user[item[0]] = {} if item[1] not in self.matrix_item: self.matrix_item[item[1]] = {} self.matrix_user[item[0]][item[1]] = item[2] self.matrix_item[item[1]][item[0]] = item[2] self.elemNum = len(triple) self.size = len(self.matrix_user), len(self.matrix_item) def row(self,r): if r not in self.matrix_user: return {} else: return self.matrix_user[r] def col(self,c): if c not in self.matrix_item: return {} else: return self.matrix_item[c] def dense_row(self,r): if r not in self.matrix_user: return np.zeros((1,self.size[1])) else: array = np.zeros((1,self.size[1])) ind = list(self.matrix_user[r].keys()) val = list(self.matrix_user[r].values()) array[0][ind] = val return array def dense_col(self,c): if c not in self.matrix_item: return np.zeros((1,self.size[0])) else: array = np.zeros((1,self.size[0])) ind = list(self.matrix_item[c].keys()) val = list(self.matrix_item[c].values()) array[0][ind] = val return array def elem(self,r,c): if not self.contain(r,c): return 0 return self.matrix_user[r][c] def contain(self,r,c): if r in self.matrix_user and c in self.matrix_user[r]: return True return False def elem_count(self): return self.elemNum def size(self): return self.size