sergeyprokudin

import tensorflow as tf
from keras.layers import Input, Dense, Flatten, Reshape, Dropout
from keras.models import Model, Sequential
from keras.optimizers import Adam
from keras.objectives import binary_crossentropy
from keras.layers.merge import concatenate
from keras.losses import mean_squared_error

def variational_autoencoder(n_input_features, latent_space_size=64, hlayer_size=256, 
                            lr=1.0e-3, kl_weight=0.1):

sergeyprokudin

import matplotlib.pyplot as plt
import scipy.stats as stats

def plot_gauss_pdf(mu, sigma, gt):
    ''' plots Guassian density together with some ground truth value gt
    '''
    x = np.linspace(mu - 5*sigma, mu + 5*sigma, 100)
    plt.plot(x, stats.norm.pdf(x, mu, sigma))
    
    plt.axvline(mu, c='blue', label='prediction mean')

sergeyprokudin

import h5py
import os

def save_h5(savepath, arr_dict):
  
    if os.path.exists(savepath):
        os.remove(savepath)

    h5ds = h5py.File(savepath)

sergeyprokudin

import matplotlib.pyplot as plt
%matplotlib inline


def plot2d(fig_lst, labels=None, figsize=(10, 10), savepath=None):
    """Plots a set of 2d shapes represented as 2d point arrays
    
    Parameters
    ----------
    fig_lst: list

sergeyprokudin

from collections import deque

def check_path(grid, i=0, j=0, failed_points=None, current_path=None):
    """ Find a route between upper-left and lower right corner of the grid,
    if you are only allowed to walk right and down.
    
    Input:
    1 1 1
    0 0 1
    0 0 1

sergeyprokudin

def count_steps(n):
    """Determine how many ways there are to walk n steps, if you can jump over 1, 2 or 3 steps at the time
    
    f(-1) = 0
    f(0) = 1 # just stand?
    f(1) = 1
    f(2) = 2 
    f(3) = 4
    f(4) = f(n-1)+f(n-2)+f(n-3)
    

sergeyprokudin

import numpy as np

def pca(x, n_components):
    """ Principal component analysis of the data
    m - number of samples
    n - number of dimensions
    k - number of components
    
    TL;DR: 
       (a) compute the covariance matrix x.T@x

sergeyprokudin

def fib(n):
    """ Compute nth element of a Fibonacci sequence:
    1, 2, 3, 5, 8, 13, 21, ...
    
    f(n) = f(n-1) + f(n-2)
    
    f(0) = 0
    f(1) = 1
    f(2) = 1
    f(3) = 2

sergeyprokudin

import heapq as hq

def sort_k_messed(a, k):
    """Sort an array where each element is at most k steps away from 
    its sorted position.
    
    Parameters:
    -----------
    a: list
        k-messed input array

sergeyprokudin

from collections import deque

def have_route(g, start_node, end_node):
    """Find out if there is a path in a directed graph g 
    between start_node and end_node
        
    Algo #1: BFS-based. 
        0. Check if start_node=end_node. If so, return True;
        1. Add start_node to queue and while queue is not empty 
            1.1. dequeue curr_node;