🚀 go-pugleaf

jtomich@IntNet.net (Jeff Tomich) wrote:

>Having a hard time to figure out a function on how to compare doubles. 
>Any ideas?

Generally something like:
#include <float.h>

	double a, b;
	/* ... */

	if ( fabs(a-b) <= DBL_EPSILON) {
		/* They're equal */
	}
	else {
		/* They're not equal... */
	}

Note that this isn't the real purpose of DBL_EPSILON, so you may need to
change the exact value used...

As you've doubtless already dicovered, a simple test for equality or
lack of it is generally meaningless with floating point numbers.

BTW, you might want to ask questions like this in comp.lang.c or
comp.lang.c.moderated -- this newsgroup is really intended for
discussion of the C standard, not normal C programming as such.
    Later,
    Jerry.

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