Don't understand day-50 portion, is there any resources for me to study? about 100days

[coells]

Hey!

In Conway's game we take each cell one by one and count up the number of activated neighbours to apply given rule. E.g. if cell is active and has less then 2 active neighbours, it is deactivated (it dies). That's an algorithm you would easily write using 3 embedded for-loops.

What you can do, instead, is to define a 2D kernel function in form

K=
[1  1 1]
[1 10 1]
[1  1 1]

The game board is another 2D function that looks like

B=
[1 0 0 0 ...]
[0 1 1 0 ...]
[0 0 0 0 ...]
[...]

Now, the convolution between two functions (board function and kernel) is defined via Fourier transform as ift(fft(B) * fft(K). And thats exactly what I do. This efectively computes the exact same think as if you would write 3 embedded for-loops, count current cells for 10 and its neighbours for 1 and sum up the values for each cell.

You certainly can use scipy.signal package to convolve the functions and ignore FT completely.

So, I think you can understand the code without knowing FT, however, since the convolution is defined in terms of FT, understanding definitely helps. On the other side, I have seen convolution to be defined and used in many areas without bothering about its relationship to FT.

FT, convolution, kernels, etc. is used in such a broad area that it's difficult to recommend any particular source.

[qiansen1386]

Thank you so much for the explanation!!