site_archiver@lists.apple.com Delivered-To: cocoa-dev@lists.apple.com On Oct 1, 2008, at 12:29 AM, Michael Robinson wrote: sin(90); returns 0 as well. When I use Apple's Calculator and ask it to tell me the result of sin(90), it gives me 1. int angle = 90; float result = sin(angle * M_PI / 180); float result = 90 / 180; float result = 90.0 / 180; or float result = (float)90 / 180; Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/site_archiver%40lists.apple... The C function sin() takes radians as its parameter. In order to use degrees you need to multiply by M_PI and divide by 180: One other thing you have to remember is that when you are doing operations with integers your result will be an integer. Doing: Will give you a value of 0. This is because a value of 0.5 will have the fractional part dropped to make it an integer. In order to retain the fractional part I need to make one of the values into a type that preserves the fractional part: Adding a decimal point or using a cast makes one of the values into a type that preserves the fractional part. Now the result of any operations will retain the fraction. In my example the constant M_PI is already a fractional type so I didn't need to do any more work to make sure the fraction was retained. _______________________________________________ This email sent to site_archiver@lists.apple.com