modf

Break down the input into fractional and integer parts and return the fractional part. The integer part is stored in the position pointed by iptr.

Interface Definition

C interface:

float modff(float x, float *iptr);

double modf(double x, double *iptr);

long double modfl(long double x, long double *iptr);

Parameters

Parameter	Type	Description	Input/Output
x	For modff, x is of single-precision floating-point type. For modf, x is of double-precision floating-point type. For modfl, x is of long double-precision floating-point type.	Floating-point value of the input data.	Input
iptr	For modff, iptr is of single-precision floating-point type. For modf, iptr is of double-precision floating-point type. For modfl, iptr is of long double-precision floating-point type.	Pointer to the integer part of the input floating-point number.	Output

Return Value

The fractional part of the input is returned. The integer part is stored in the position pointed by iptr.

Dependency

C: "km.h"

Example

C interface:

    // typical usage
    double iptr;
    printf("modf(3.4, &iptr) = %.15f, iptr = %.15f\n", modf(3.4, &iptr), iptr);
    printf("modf(-4.8, &iptr) = %.15f, iptr = %.15f\n", modf(-4.8, &iptr), iptr);


result
    /* 
     * modf(3.4, &iptr) = 0.400000000000000, iptr = 3.000000000000000
     * modf(-4.8, &iptr) = -0.800000000000000, iptr = -4.000000000000000
     * */

Parent topic: Rounding Functions