acosd32(), acosd64(), acosd128() - Calculate arccosine

Standards

Standards / Extensions	C or C++	Dependencies
C/C++ DFP	both	z/OS® V1.10

Format

#define __STDC_WANT_DEC_FP__
#include <math.h>

_Decimal32  acosd32(_Decimal32 x);
_Decimal64  acosd64(_Decimal64 x);
_Decimal128 acosd128(_Decimal128 x);
_Decimal32  acos(_Decimal32 x);      /* C++ only */
_Decimal64  acos(_Decimal64 x);      /* C++ only */
_Decimal128 acos(_Decimal128 x);     /* C++ only */

General description

Calculates the arccosine of x, expressed in radians, in the range 0 to pi.

The value of x must be between -1 and 1 inclusive.

These functions work in IEEE decimal floating-point format. See IEEE decimal floating-point for more information.

Note: To use IEEE decimal floating-point, the hardware must have the Decimal Floating-Point Facility installed.

Returned value

If successful, the function returns the arccosine of the argument x.

If x is less than -1 or greater than 1, the function sets errno to EDOM and returns NaNQ. No other errors will occur.

Example

CELEBA11

⁄* CELEBA11

   The example illustrates the acosd32() function.

   This example prompts for a value for x.
   It prints an error message if x is greater than 1 or
   less than -1; otherwise, it assigns the arccosine of
   x to y.

*⁄

#define __STDC_WANT_DEC_FP__
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define MAX  1.0DF
#define MIN -1.0DF

int main(void)
{
   _Decimal32 x, y;

   printf( "Enter x\n" );
   scanf( "%Hf", &x );

   ⁄* Output error if not in range *⁄
   if ( x > MAX )
      printf( "Error: %f too large for acosd32\n", x );
   else if ( x < MIN )
      printf( "Error: %f too small for acosd32\n", x );
   else {
      y = acosd32( x );
      printf( "acosd32( %Hf ) = %Hf\n", x, y );
   }
}