Q:

More then 53-bit floating point precision in php?

Possible Duplicate:
How do I work with high precision decimals in PHP 

For a mandelbrot fractal I need more floating-point precision then just 53-bit in php. Is this possible? I've read this post about php floating-point but it's hard to understand: http://www.mysqlperformanceblog.com/2008/01/10/php-vs-bigint-vs-float-conversion-caveat/ 

A:

If you're looking at floating point numbers, I think you're probably limited to PHP's native double precision (53-odd bits of precision) floats or the BC Math stuff (arbitrary precision).
They also have a GMP extension as well but I've had the GMP stuff die violently on me in low memory situations, something I find unforgivable in a general purpose library. Still, if you avoid those situations, it is blindingly fast. The PHP package only seems to support the integer side of GMP currently so you'd have to work with scaled integers (ie, fixed point) to get non-integer functionality. That may be more trouble than it's worth.

