#47633 [Opn]: Bcmath precision issue

ID: 47633 User updated by: k1ngrs at ntlworld dot com Reported By: k1ngrs at ntlworld dot com Status: Open Bug Type: BC math related Operating System: Windows XP Pro SP2 PHP Version: 5.2.9 New Comment: I think I have uncovered the reason for the issue and that is that the function expects a string and I have passed a floating point number which OK to a point. Once you go smaller than 0.0001 you transfer a scientific notation to the function that does not compute. So the answer is to convert it first using number_format. Regards Rob Previous Comments: ------------------------------------------------------------------------ [2009-03-12 11:59:00] k1ngrs at ntlworld dot com Description: ------------ The bcmath commands do not seem to work for numbers smaller than 0.0001 for exmaple if you add 0.00001 and 0.00001 the result is zero. Even setting the bcscale beforehand does not fix the issue. Reproduce code: --------------- <?php $a =bcadd(0.00011,0.00011,6); $b =bcadd(0.00001,0.00001,6); $c =bcsub((double)0.00001,(double)0.000005,6); echo "1. 0.00011 + 0.00011 = $a OK\r\n"; echo "2. 0.00001 + 0.00001 = $b Wrong\r\n"; echo "3. 0.00001 - 0.000005 = $c Wrong\r\n"; ?> Expected result: ---------------- 1. 0.00011 + 0.00011 = 0.000220 2. 0.00001 + 0.00001 = 0.00002 3. 0.00001 - 0.000005 = 0.000005 Actual result: -------------- 1. 0.00011 + 0.00011 = 0.000220 OK 2. 0.00001 + 0.00001 = 0.000000 Wrong 3. 0.00001 - 0.000005 = 0.000000 Wrong ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=47633&edit=1