Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mit-eddie!uw-beaver!blake!oregon!michelbi
From: michelbi@oregon.uoregon.edu (Michel Biedermann)
Newsgroups: comp.lang.c
Subject: Answer to rounding any number to a given decimal point
Message-ID: <3009@oregon.uoregon.edu>
Date: 23 May 89 06:18:17 GMT
Organization: University of Oregon
Lines: 13

Here is the most elegant answer to the problem of rounding-off an arbitrary
number to an arbitrary decimal level.
 
#define round(x,y) ((x < 0.0F?  ceil((x)/(y)-.5F)*(y) : floor((x)/(y)+.5F)*(y)))

round(1.5555,.1)	will return 1.6
round(-1.555,.1)	will return -1.6
round(.502,.01)		will return .50

Credit is due to Steve Emmerson (steve@umigw.miami.edu).  Thanks Steve...
 
Michel Biedermann
U. of Oregon