anyway, is there a way to make my program only works on eg. 3 decimal precision? so in result, everytime I do a floating point precision, it always truncated after 3 decimal. thx in advance :)
================================= http://www.svnstrk.blogspot.com ================================= --- On Mon, 5/25/09, Jos Timanta Tarigan <[email protected]> wrote: From: Jos Timanta Tarigan <[email protected]> Subject: Re: [c-prog] Re: limiting precision on float To: [email protected] Date: Monday, May 25, 2009, 2:17 AM hi sorry I mean angleX + 90 = 90 which means angleX = 0 my PI_RADIAN is 0.01745329251994329 58 ( I copied it from a site :D ) so i googled around and seemed that I can only do this two ways1. deal with string and use setPrecision and then convert back to double2. muliply, int, and divide to float eg. want to get 3 decimal, multiply by 1000, convert to int, and then divide with 1000 to float. which one dyou think is faster? Im gonna do this calculation a lot like 300 times / second :DÂ ============ ========= ========= === http://www.svnstrk. blogspot. com ============ ========= ========= === --- On Sun, 5/24/09, peternilsson42 <peternilsson42@ yahoo.com> wrote: From: peternilsson42 <peternilsson42@ yahoo.com> Subject: [c-prog] Re: limiting precision on float To: c-p...@yahoogroups. com Date: Sunday, May 24, 2009, 11:06 PM --- In c-p...@yahoogroups. com, Jos Timanta Tarigan <jos_t_tarigan@ ...> wrote: > > hi, > im currently having a problem try to calculate this: > directionZ = -cos((angleX+ 90)*PI_RADIAN) ; What is PI_RADIAN? [I'll assume (PI/180).] You could try... directionZ = -cos((angleX+ 90)/180.* PI); Or more simply... directionZ = sin(angleX/180. *PI); Better still would be to work in radians entirely, though that won't remove all the issues. > most of the time it works but when im in the boundary > of the coordinate, it gives me a little error that im > not expecting if calculated correctly. i notice that > when my angleX is 90, and my directionZ should be 0. Really? The cosine of 180 degrees is -1 on my planet. ;) -- Peter [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]
