Re: More math fun

On Wed, 2008-08-13 at 07:47 -0700, Jim Lucas wrote: > Jay Blanchard wrote: > > [snip] > >> 1.7763568394E-15 is 0. The computer just had a rounding error > > somewhere. We > >> had this discussion a few weeks ago, the solution being to decide to > > what > >> accuracy you want the answer. Upto 14 decimal places will give you 0 > > here!! > > > > I thought we had a different discussion a couple of weeks ago about > > floating point storage precision. How come only Jay is getting *this* > > rounding error? > > [/snip] > > > > Perhaps it is the PHP version? I have tried this on three separate PHP > > installations (all the same configs) and got the same results. I will > > look to see if there is an upgraded version. > > > > When applying round to the numbers everything works out as expected, but > > makes me uncomfortable. > > > > What is your precision in your php.ini file set to? Default is 14. If it is > set to 16 or greater, then it would display the reseults you are seeing. Mine > is set to 14, so it would automatically round it to 0. I think. > > I will test, brb...... > > hmmm weird, if I set my precision to 20 and restart, I still get 0 for the > value. Odd, I would have thought it would have then shown me the expected value. I tried the highest precision setting that PHP appears to honour... 54. I still get 0 :) Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP