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kml_sparse_?gthr

Gather the elements specified in full-storage sparse vector y to a vector that is in compressed form.

x[i]=y[indx[i]], i=0,1, ..., nz-1

Interface Definition

C interface:

kml_sparse_status_t kml_sparse_sgthr(const KML_INT nz, const float *y, float *x, const KML_INT *indx);

kml_sparse_status_t kml_sparse_dgthr(const KML_INT nz, const double *y, double *x,const KML_INT *indx);

kml_sparse_status_t kml_sparse_cgthr(const KML_INT nz, const KML_Complex8 *y, KML_Complex16 *x, const KML_INT *indx);

kml_sparse_status_t kml_sparse_zgthr(const KML_INT nz, const KML_Complex16 *y, KML_Complex16 *x, const KML_INT *indx);

Fortran interface:

RES = KML_SPARSE_SGTHR(NZ, Y, X, INDX);

RES = KML_SPARSE_DGTHR(NZ, Y, X, INDX);

RES = KML_SPARSE_CGTHR(NZ, Y, X, INDX);

RES = KML_SPARSE_ZGTHR(NZ, Y, X, INDX);

Parameters

Parameter

Type

Description

Input/Output

nz

Integer

Number of elements in the x and indx arrays

Input

y
  • For sgthr, y is a single-precision floating-point array.
  • For dgthr, y is a double-precision floating-point array.
  • For cgthr, y is a single-precision complex array.
  • For zgthr, y is a double-precision complex array.

Array y. The size is at least max(indx[i]).

Input

x
  • For sgthr, x is a single-precision floating-point array.
  • For dgthr, x is a double-precision floating-point array.
  • For cgthr, x is a single-precision complex array.
  • For zgthr, x is a double-precision complex array.

Array x for storing non-zero elements. The size is at least nz.

Input/Output

indx

Integer array

indx[i] indicates the serial number of the ith element in the x array in the dense vector. The array size is at least nz.

Input

Return Value

Function execution status. The enumeration type is kml_sparse_status_t.

Dependencies

C: "kspblas.h"

Fortran: "kspblas.f03"

Examples

C interface:

    KML_INT nz = 2; 
    KML_INT indx[2] = {1,2}; 
    float x[2] = {0,0}; 
    float y[4] = {-1, 5, -2 ,3}; 
    kml_sparse_status_t status = kml_sparse_sgthr(nz,y,x,indx); 
 
    /* 
     *  Output x: 
     *     5.000000    -2.000000 
     */

Fortran interface:

    INTEGER(C_INT) :: NZ = 2 
    INTEGER(C_INT) :: INDX(2) 
    INTEGER(C_INT) :: STATUS 
    REAL(C_FLOAT) :: X(2), Y(4) 
    DATA INDX/1,2/ 
    DATA X/0,0/ 
    DATA Y/-1, 5, -2 ,3/ 
    STATUS = KML_SPARSE_SGTHR(NZ,Y,X,INDX); 
    ! 
    !  OUTPUT X: 
    !     5.000000    -2.000000 
    !