Solar Powered Conways Game of Life
davidhampgonsalves.com
davidhampgonsalves.com
From "Building arbitrary Life patterns in 15 gliders" (2022) https://news.ycombinator.com/item?id=33799981 :
> From "Convolution Is Fancy Multiplication" https://news.ycombinator.com/item?id=25194658 :
>> FWIW, (bounded) Conway's Game of Life can be efficiently implemented as a convolution of the board state: https://gist.github.com/mikelane/89c580b7764f04cf73b32bf4e94... ; scipy.ndimage.convolve
> Conway's Game is a 2D convolution
> Convolution theorem: https://en.wikipedia.org/wiki/Convolution_theorem
Conway's Game of Life > Algorithms: https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life#Algori...
Rosetta Code > Conway's Game of Life: http://rosettacode.org/wiki/Conway%27s_Game_of_Life
From https://github.com/thearn/game-of-life :
> How it's written
> The game grid is encoded as a simple m by n array (default 100x100 in the code) of zeros and ones. In each program, a state transition is determined for each pixel by looking at the 8 pixel values all around it, and counting how many of them are "alive", then applying some rules based that number. Since the "alive" or "dead" states are just encoded as 1 or 0, this is equivalent to summing up the values of all 8 neighbors.
> If you want to do this for all pixels in a single shot, this is equivalent to computing the 2D convolution between the game state array and the matrix [[1,1,1],[1,0,1],[1,1,1]]. Convolution is an operation that basically applies that matrix as a "stencil" at every position around the game grid array, and sums up the values according to the values in that stencil. And convolution can be very efficiently computed using the FFT, thanks to the Fourier Convolution Theorem.
> One side effect: the convolution using FFT implicitly involves periodic boundary conditions, so the game grid is "wrapped" around itself (like in Pacman, or Mario Bros. 2). If you wanted to change this, you would just have to modify the 2D convolution function to use an orthogonal form of the DCT instead of the FFT. This would correspond to "hard" (i.e. Dirichlet) boundary conditions on the convolution operator.
> I think you could do this with scipy using the 1D orthogonal dct provided:
from scipy import fftpack
fftpack.dct(data, norm='ortho')
> but I haven't tried that yet. You'd have to define a dct2() method using fftpack.dct and separability (ie. the 1D transform matrix is rank-one, and the 2D transform operator is the Kronecker product of two 1D transforms)The (Inverse) Quantum Fourier Transform is also applied in QC; https://en.wikipedia.org/wiki/Quantum_Fourier_transform#Defi...
Solar power: https://en.wikipedia.org/wiki/Solar_power
Because I've added edges from hn_uri to wikipedia_uris; I, others, and search engines could discover the hn_uris relevant to the concept URIs (by graph pattern search)
W3C SPARQL is a graph pattern query language. Some triple graph patterns enabled by there being links in the comments here in HN:
?s ?p ?o.
?s linksTo ?o.
?s linksTo <wikipedia_uri> .
Also, recently, for example, because I linked to "methane" on Wikipedia unnecessarily, and then checked the "See also" section, and then saw the "Global Methane Initiative" page, I realized that there was an opportunity to forward the latest methane emissions tech to GMI (which I learned about by reading comparatively mundane background information from Wikipedia, which has Concept URIs which are reused by DBpedia which contributes to the Linked Open Data cloud for indeed what returns)