Wanted: fast, low-precision trig functions for C

[Ted A. Campbell]

I am writing a graphics-based program that has to calculate 
several thousand map coordinates.  The slowest part of this 
program by far is its trigonometric functions--it takes 
3 minutes and 45 seconds to calculate 3000 sets ofd coordinates
on an XT clone at 10 mhz (no coprocessor), which is the lowest 
resolution map I can make.  

I wondered if there were any fast, low-precision approaches 
to the standard trig functions, since the compilers I use
(Microsoft QuickC and AT&T Unix C) boast of their high 
level of precision?  

Any suggestions will be appreciated.  Thanks.  

Ted A. Campbell
Duke Divinity School 
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