modf, modff : split fractional and integer parts

Synopsis

#include <math.h>
double modf(double val, double *ipart);
float modff(float val, float *ipart);
```### Description

modf splits the double val apart into an integer part and a fractional part, returning the fractional part and storing the integer part in *ipart. No rounding whatsoever is done; the sum of the integer and fractional parts is guaranteed to be exactly equal to val. That is, if . realpart = modf(val, &intpart); then `realpart+intpart' is the same as val. modff is identical, save that it takes and returns float rather than double values.### Returns

The fractional part is returned. Each result has the same sign as the supplied argument val.

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**Authoritative source**: BUSMASTER DITA help source `modf.dita`, compiled into `BUSMASTER.CHM` with the application.