scipy.signal.correlate2d 3rd party solution for Identify Block by Rcp8jzd - python coding challenges

Enable Javascript in your browser and then refresh this page, for a much enhanced experience.

scipy.signal.correlate2d solution in 3rd party category for Identify Block by Rcp8jzd

import numpy as np
from scipy.signal import correlate2d

BLOCKS = {'I': [[1],
                [1],
                [1],
                [1]],
          'J': [[0, 1],
                [0, 1],
                [1, 1]],
          'L': [[1, 0],
                [1, 0],
                [1, 1]],
          'O': [[1, 1],
                [1, 1]],
          'S': [[0, 1, 1],
                [1, 1, 0]],
          'T': [[1, 1, 1],
                [0, 1, 0]],
          'Z': [[1, 1, 0],
                [0, 1, 1]]}


def identify_block(numbers):
    """ Identify a Tetris block in a 4x4 grid based on the tiles numbers.
    Return None if no Tetris block is found """
    grid = np.zeros(16)
    for index in numbers:
        grid[index - 1] = 1
    grid.resize((4, 4))
    for name, shape in BLOCKS.items():
        # For each block, try every rotation until match is found
        for rotation in range(4):
            correlation = correlate2d(grid, shape, mode='valid')
            if (correlation == 4).any():
                return name
            shape = np.rot90(shape)
    return None

April 13, 2020

Comments:

vvm70 on July 2, 2020, 5:05 p.m.
5 This code isn't clear. What does the correlate2d() function do?

vvm70 on July 2, 2020, 5:24 p.m.
This code isn't clear. What does the correlate2d() function do?

vvm70 on July 2, 2020, 5:25 p.m.
This code isn't clear. What does the correlate2d() function do?

Rcp8jzd on July 2, 2020, 7:39 p.m.
The correlate2d() function computes the cross correlation between the grid and the pattern. Cross correlation is especially useful in image processing, when you want to locate a detail in an image. Here, correlate2d() is evaluated at every position where the tetris block could be (parameter mode=’valid’). At this position, the cross correlation is equal to the sum of the element-wise product of the region of the grid and the tetris block. If this sum equals 4, then all 4 blocks of the tetris block match and we found the right tetris block. For more information on this function, see <a href="https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.correlate2d.html?highlight=correlate2d#scipy.signal.correlate2d">the documentation</a> I agree with you, this may be not clear if you are not familiar with image processing.

Blizzard

0 %

You ClassRoom Demo is Ready With the new tool CheckiO ClassRoom, you will be able to analyze your students' progress, have your own leaderboard, change missions order on the map, and so on.