# Re: Random number generators

"Ron Shepard" <ron-shepard@xxxxxxxxxxxxxxxxxx> wrote in message
news:ron-shepard-C17E22.01284221112009@xxxxxxxxxxxxxxxxxxxxx

| In binary floating point, are the same number of (equally spaced)
| values between .25 and .50 as there are between .50 and 1.0. Then
| there are that same number of values between .125 and .25, and that
| same number of values again between .0625 and .125, and so on, all
| the way down to the minimum exponent value. In most formats, there
| are about the same number of exponents less than zero as there are
| greater than zero, so about half of the exponent range corresponds
| to floating point values that are between 0 and .5, and only a
| single exponent value corresponds to the floating point values
| between .5 and 1.
|
| For a given exponent, should a PRNG return all of the associated
| floating point values with equal probability, or only some of them?

Probably a case for integer RNGs.

.

## Relevant Pages

• Re: representations
... The exponent is the exponent, ... IEEE standard floating point number use something very similar to scientific notation. ... There is one exception to this rule, zero, so zero is represented specially by all bits zero. ... Finally there are a few special representations for infinity, not a number, and what are called denormalised numbers, but you can ignore those for now. ...
(comp.lang.c)
• Re: 32 bit floating point
... PCs typically used IEEE 754 floating point, ... mantissa. ... positive, one if negative, 6 is the exponent, and 1.234 is the ... value it supports is positive zero (thought evidently you can have ...
(comp.lang.apl)
• Re: fixed-point
... First ask yourself "what is the purpose of a floating point number?" ... Adjust the numbers so that both numbers have the same exponent ... The 16 in the macro refers to the multiplication factor. ... function call in so far as the paramter conversion is concerned. ...
(comp.lang.c)
• Re: Fastest way to compute floating point log and exp
... So far I've found that with a few tables and floating point MUL and ADD ... You didn't mention how much precision you need, nor for that matter what the log base is to be. ... bit easier than other bases because the floating point exponent is the integer portion of the log. ...
(comp.arch.fpga)
• Re: zero up memory
... An architecture where zero bits don't make a 0.0 floating point value ... Zero cannot be represented in floating point, because the exponent is ... IEEE decimal floating point ...
(comp.lang.c)