Documentation
Rate This Document
Findability
Accuracy
Completeness
Readability
SubmitClose

?asum

Sum up the absolute values of vector elements. For the complex numbers, the absolute values of the real part and imaginary part are summed.

Interface Definition

C interface:

float cblas_sasum(const BLASINT n, const float *x, const BLASINT incx);

double cblas_dasum(const BLASINT n, const double *x, const BLASINT incx);

float cblas_scasum(const BLASINT n, const void *x, const BLASINT incx);

double cblas_dzasum(const BLASINT n, const void *x, const BLASINT incx);

Fortran interface:

RES = SASUM(N, X, INCX)

RES = DASUM(N, X, INCX)

RES = SCASUM(N, X, INCX)

RES = DZASUM(N, X, INCX)

Parameters

Parameter

Type

Description

Input/Output

n

Integer

Number of elements in vector x

Input

x
  • For dasum, x is of double-precision floating-point type.
  • For sasum, x is of single-precision floating-point type.
  • For scasum, x is of single-precision complex number type.
  • For zasum, x is of double-precision complex number type.

Vector x. The vector size is at least (1+(n-1)*abs(incx)).

Input

incx

Integer

Increment for the elements of vector x

Input

Dependencies

#include "kblas.h"

Examples

C interface:

    int n = 5, incx = 1, incy = 1; 
    /* 
     *  Input X:  0.340188, -0.105617, 0.283099, 0.298440, 0.411647 
     */ 
    float x[5] = {0.340188, -0.105617, 0.283099, 0.298440, 0.411647}; 
 
    float res = cblas_sasum(n, x, incx);
    /* 
     *  Output : 1.438991 
     */

Fortran interface:

      INTEGER :: N=5 
      INTEGER :: INCX=1 
      REAL(4) X(5) 
      DATA X /0.340188, -0.105617, 0.283099, 0.298440, 0.411647/ 
      RES=SASUM(N,X,INCX) 
 
*     Output : 1.438991