Date: Fri, 11 Jul 1997 22:36:30 -0700 (PDT)
Message-Id: <199707120536.WAA15679@adit.ap.net>
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To: dgmdavies AT onaustralia DOT com DOT au
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: math.h sin() function returns wrong value
Cc: djgpp AT delorie DOT com
Precedence: bulk

You wrote:
>[deleted, but includes lines such as:]
>  printf("sin(45) = %f\n", sin(45));
>If I enter 32 as the angle, the
>converted angle is 45, which is right, and then when I call the sin()
>function I get a completely different answer.  
The sin() function takes its arguments in *radians*. If you don't know what
radians are, read on.
Radians are an angle measuring unit, there are (2*PI) radians in a full
circle (360 degrees). Thus, here are some macros for converting between the two:
#define degtorad(x) (((double)x / 360) * (2 * PI)) /* PI defined in math.h */
#define radtodeg(x) (((double)x / (2 * PI)) * 360)

>Do I need to get djgpp version 3?  At the moment, I've got version 2.
Version 3 does not exist yet. The newest version is 2.01.

HTH

Nate Eldredge
eldredge AT ap DOT net