Edit report at https://bugs.php.net/bug.php?id=60548&edit=1
ID: 60548 Updated by: cataphr...@php.net Reported by: ronaldoklais at gmail dot com Summary: Problema com cálculo -Status: Open +Status: Bogus Type: Bug Package: Math related Operating System: Windows XP PHP Version: Irrelevant Block user comment: N Private report: N New Comment: To be expected. Use multiplication instead ($v = $v_initial + $a * $i), that way the rounding errors won't accumulate. Previous Comments: ------------------------------------------------------------------------ [2011-12-16 21:35:06] ronaldoklais at gmail dot com Description: ------------ Problema com cálculo Test script: --------------- <? $v = 10; $i = -0.15; for ($a = 0; $a < 100; $a++) { $v += $i; echo $v, '<br>'; } ?> Actual result: -------------- 9.85 9.7 9.55 9.4 9.25 9.1 8.95 8.8 8.65 8.5 8.35 8.2 8.05 7.9 7.75 7.6 7.45 7.3 7.15 7 6.85 6.7 6.55 6.4 6.25 6.1 5.95 5.8 5.65 5.5 5.35 5.2 5.05 4.9 4.75 4.6 4.45 4.3 4.15 4 3.85 3.7 3.55 3.4 3.25 3.1 2.95 2.8 2.65 2.5 2.35 2.2 2.05 1.9 1.75 1.6 1.45 1.3 1.15 0.99999999999999 0.84999999999999 0.69999999999999 0.54999999999999 0.39999999999999 0.24999999999999 0.099999999999988 -0.050000000000012 -0.20000000000001 -0.35000000000001 -0.50000000000001 -0.65000000000001 -0.80000000000001 -0.95000000000001 -1.1 -1.25 -1.4 -1.55 -1.7 -1.85 -2 -2.15 -2.3 -2.45 -2.6 -2.75 -2.9 -3.05 -3.2 -3.35 -3.5 -3.65 -3.8 -3.95 -4.1 -4.25 -4.4 -4.55 -4.7 -4.85 -5 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=60548&edit=1