I'm having a problem with the fmod() function.
This code should be true, but somehow it's not. Any help?
if (fmod(1.9, 0.3) == 0.1) {
cout << "True." << endl;
}
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Mathew Block
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ParkerR
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3Floating-point arithmetic is inexact. – Keith Thompson Sep 05 '13 at 23:04
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I would suggest you to refer to [this question](http://stackoverflow.com/questions/17333/most-effective-way-for-float-and-double-comparison) before trying anything. – Laurent Jalbert Simard Sep 05 '13 at 23:15
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...not exact... as would be shown by doing cout<
– pm100 Sep 05 '13 at 23:16
1 Answers
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Floating point number aren't exact. One way you could do this is,
#include <limits>
if (fabs(fmod(1.9,0.3) - 0.1) < std::numeric_limits<double>::epsilon()) {
cout << "True." << endl;
}
However, this is a crude solution that isn't entirely correct. Do a few searches for how to compare doubles/floats on stackoverflow for some discussions on the issue.
PherricOxide
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