kml_sparse_?dotui_sub

Compute the non-conjugate dot product of complex vectors (Euclidean space). x · y = xˆT * y. That is, multiply an element in vector x by the corresponding element in vector y and then add the products.

res = x[0] * y[indx[0]] + x[1] * y(indx[1]) + ... + x[nz - 1] * y[indx[nz - 1]]

Interface Definition

C interface:

kml_sparse_status_t kml_sparse_cdotui_sub(const KML_INT nz, const KML_Complex8 *x, const KML_INT *indx, const KML_Complex8 *y, KML_Complex8 *dotui);

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

Fortran interface:

RES = KML_SPARSE_CDOTUI_SUB(NZ, X, INDX, Y, DOTUI);

RES = KML_SPARSE_ZDOTUI_SUB(NZ, X, INDX, Y, DOTUI);

Parameters

Parameter	Type	Description	Input/Output
nz	Integer	Number of elements in the x and indx arrays.	Input
x	For cdotui, x is a single-precision floating-point array. For zdotui, x is a double-precision floating-point array.	Array x for storing non-zero elements. The size is at least nz.	Input
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
y	For cdotui, y is a single-precision floating-point array. For zdotui, y is a double-precision floating-point array.	Array y. The size is at least max(indx[i]).	Input
dotui	For cdotui, doti is of the single-precision floating-point type. For zdotui, doti is of the double-precision floating-point type.	Dot product of x and y.	Input/Output

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_Complex8 dotui = {0,0}; 
    KML_INT indx[2] = {1, 2}; 
    KML_Complex8 x[2] = {{1, 2}, {3, 4}}; 
    KML_Complex8 y[4] = {{-1, 1}, {5, 3}, {-2, -3}, {4, 1}}; 
    kml_sparse_status_t status = kml_sparse_cdotui_sub(nz, x, indx, y, &dotui); 
 
    /* 
     *  Output dotui: 
     *     {5.000000, -4.000000} 
     */

Fortran interface:

    INTEGER(C_INT) :: NZ = 2 
    INTEGER(C_INT) :: STATUS 
    INTEGER(C_INT) :: I 
    TYPE(KML_COMPLEX8), TARGET :: DOTUI = KML_COMPLEX8(0, 0) 
    INTEGER(C_INT) :: INDX(2) 
    TYPE(KML_COMPLEX8) :: CX(2), Y(4) 
    REAL(C_FLOAT) :: X(4), Y(8) 
    TYPE(C_PTR) :: PDOTCUI 
    PDOTUI = C_LOC(DOTUI) 
    DATA INDX/1, 2/ 
    DATA X/1, 2, 3, 4/ 
    DATA Y /-1, 1, 5, 3, -2, -3, 4, 1/ 
    I = 1 
    DO WHILE(I <= 2) 
        CX(I)%REAL = X(2 * I - 1) 
        CX(I)%IMAG = X(2 * I) 
    END DO 
    I = 1 
    DO WHILE(I <= 4) 
        CY(I)%REAL = Y(2 * I - 1) 
        CY(I)%IMAG = Y(2 * I) 
    END DO 
    STATUS = KML_SPARSE_CDOTUI_SUB(NZ, CX, INDX, CY, PDOTUI) 
    ! 
    !  OUTPUT DOTCI: 
    !     {5.000000, -4.000000} 
    !

Parent topic: Sparse BLAS Level 1 Functions