alibSubt

RWalib C Array Library User Guide > Arithmetic Operations > alibSubt

alibSubt

Subtracts scalar or array arguments, element-wise. The PV-WAVE API for this routine is the Subtraction Operator -.

Prototypes

void alibSubtb( wvlong m, wvlong n, UCHAR *p, UCHAR *q, UCHAR *r )

void alibSubts( wvlong m, wvlong n, short *p, short *q, short *r )

void alibSubti( wvlong m, wvlong n, int *p, int *q, int *r )

void alibSubtl( wvlong m, wvlong n, wvlong *p, wvlong *q, wvlong *r )

void alibSubtf( wvlong m, wvlong n, float *p, float *q, float *r )

void alibSubtd( wvlong m, wvlong n, double *p, double *q, double *r )

void alibSubtc( wvlong m, wvlong n, COMPLEX *p, COMPLEX *q, COMPLEX *r )

void alibSubtz( wvlong m, wvlong n, DCOMPLEX *p, DCOMPLEX *q, DCOMPLEX *r )

Parameters

m — (Input) The number of elements in the first array operand. A value of 0 indicates that the first operand is a scalar.

n — (Input) The number of elements in the second array operand. A value of 0 indicates that the second operand is a scalar. If both operands are arrays then n must equal m.

*p — (Input) The pointer to the first operand.

*q — (Input) The pointer to the second operand.

*r — (Input/Output) The destination array. On return, array r contains the element-wise difference of the two operands. The operation can be done in-place, i.e., r can equal p or q.

Example

#include <stdio.h>

#include <stdlib.h>

#include <math.h>

#include "alib.h"

void main() {

  /* make up some input data for the examples */

    short    s0[6]={2,3,4,5,6,7}, s1[6]={7,2,6,3,5,3}, s2=5;

  /* make an output array */

    short    s[6];

  printf( "\n\n show 6-element vector s0 and scalar s2" );

    alibinit( NULL, NULL, NULL, NULL );

    alibPrintArrays( 1, 1, 1, 6, s0, NULL );

    alibPrintArrays( 1, 1, 1, 1, &s2, NULL );

  printf( "\n\n show the result of s0 - s2, element-wise" );

    alibSubts( 6, 0, s0, &s2, s );

    alibPrintArrays( 1, 1, 1, 6, s, NULL );

  printf( "\n\n show the result of s2 - s0, element-wise" );

    alibSubts( 0, 6, &s2, s0, s );

    alibPrintArrays( 1, 1, 1, 6, s, NULL );

  printf( "\n\n show a second 6-element vector s1" );

    alibPrintArrays( 1, 1, 1, 6, s1, NULL );

  printf( "\n\n show the result of s0 - s1, element-wise" );

    alibSubts( 6, 6, s0, s1, s );

    alibPrintArrays( 1, 1, 1, 6, s, NULL );

  printf( "\n\n now do the same operation, but in-place in s0, \n" );

  printf( " and show the result as a (2,3) matrix" );

    alibSubts( 6, 6, s0, s1, s0 );

    alibPrintArrays( 1, 1, 2, 3, s0, NULL );

Output:

 show 6-element vector s0 and scalar s2

       2       3       4       5       6       7

 show the result of s0 - s2, element-wise

      -3      -2      -1       0       1       2

 show the result of s2 - s0, element-wise

       3       2       1       0      -1      -2

 show a second 6-element vector s1

       7       2       6       3       5       3

 show the result of s0 - s1, element-wise

      -5       1      -2       2       1       4

 now do the same operation, but in-place in s0,

 and show the result as a (2,3) matrix

      -5       1      -2

       2       1       4

Version 2017.0