Random Number Generator visual analysis

Don't know if that of any use to be on PolyMath but I found that quick & dirty way of rapidly detecting if a RNG suffers from big problems.  Can be useful if, with a single glance, you can avoid running a gazillion statistical tests for nothing since the RNG is obviously broken.  Just try the following code in a workspace :

"References:
https://www.random.org/analysis/
https://boallen.com/random-numbers.html
"
| form colors yourFavoriteRNG size |

size := 512.
yourFavoriteRNG := Random new.

colors := Array with: Color white with: Color black.
form := Form extent: size@size depth: 32.

0 to: (size-1) do: [ :x |
    0 to: (size-1) do: [ :y | form colorAt: (x@y) put: (colors atRandom: yourFavoriteRNG) ] ].
PNGReadWriter putForm: form onFileNamed: 'test.png'.