Question

I am reading random bytes from /dev/urandom, and I want to make a random float out of it/them. How would I do this? I can convert the byte to a number with ord(), and it’s between 0 and 255.

It’s obvious that 255 is 1.0, 127 is 0.5 and 0 is 0.0, but how do I calculate the rest? Also, I think one byte is not enough to give lots of precision? How many bytes should I use for this?

Answer 1

Try the simple linear relationship

$f = $r / 255.0;

where $r is the random byte, and $f is the random float.

This way, when $r=255, $f is 1.0 and when $r=127, $f is 0.498

to get 0.5 for r=127 would require a different relationship.