log10d32(), log10d64(), log10d128() — Calculate base 10 logarithm
Standards
Standards / Extensions | C or C++ | Dependencies |
---|---|---|
C/C++ DFP | both | z/OS® V1.8 |
Format
#define __STDC_WANT_DEC_FP__
#include <math.h>
_Decimal32 log10d32(_Decimal32 x);
_Decimal64 log10d64(_Decimal64 x);
_Decimal128 log10d128(_Decimal128 x);
_Decimal32 log10(_Decimal32 x); /* C++ only */
_Decimal64 log10(_Decimal64 x); /* C++ only */
_Decimal128 log10(_Decimal128 x); /* C++ only */
General description
Calculates the base
10 logarithm of the positive value of x.
Notes:
- To use IEEE decimal floating-point, the hardware must have the Decimal Floating-Point Facility installed.
- These functions work in IEEE decimal floating-point format. See "IEEE Decimal Floating-Point" for more information.
Returned value
If successful, the function returns the base 10 logarithm of the positive value of x.
If x is negative, the function sets errno to EDOM and returns NaNQ.
If x is 0, the function returns -HUGE_VAL_D32, -HUGE_VAL_D64, or -HUGE_VAL_D128 and errno remains unchanged.
Example
/* CELEBL23
This example illustrates the log10d128() function.
*/
#define __STDC_WANT_DEC_FP__
#include <math.h>
#include <stdio.h>
int main(void)
{
_Decimal128 x = 1000.0DL, y;
y = log10d128(x);
printf("The base 10 logarithm of %DDf is %DDf\n", x, y);
}