Developer Reference for Intel® oneAPI Math Kernel Library for C
p?lase2
Initializes an m -by- n distributed matrix.
Syntax
void pslase2 ( constchar*uplo , constMKL_INT*m , constMKL_INT*n , constfloat*alpha , constfloat*beta , float*a , constMKL_INT*ia , constMKL_INT*ja , constMKL_INT*desca );
void pdlase2 ( constchar*uplo , constMKL_INT*m , constMKL_INT*n , constdouble*alpha , constdouble*beta , double*a , constMKL_INT*ia , constMKL_INT*ja , constMKL_INT*desca );
void pclase2 ( constchar*uplo , constMKL_INT*m , constMKL_INT*n , constMKL_Complex8*alpha , constMKL_Complex8*beta , MKL_Complex8*a , constMKL_INT*ia , constMKL_INT*ja , constMKL_INT*desca );
void pzlase2 ( constchar*uplo , constMKL_INT*m , constMKL_INT*n , constMKL_Complex16*alpha , constMKL_Complex16*beta , MKL_Complex16*a , constMKL_INT*ia , constMKL_INT*ja , constMKL_INT*desca );
Include Files
mkl_scalapack.h
Description
p?lase2 initializes an m -by- n distributed matrix sub( A ) denoting A ( ia : ia + m -1, ja : ja + n -1) to beta on the diagonal and alpha on the off-diagonals. p?lase2 requires that only the dimension of the matrix operand is distributed.
Input Parameters
- uplo
-
(global) CHARACTER. Specifies the part of the distributed matrix sub( A ) to be set: = ‘U’: Upper triangular part is set; the strictly lower triangular part of sub( A ) is not changed; = ‘L’: Lower triangular part is set; the strictly upper triangular part of sub( A ) is not changed; Otherwise: All of the matrix sub( A ) is set.
- m
-
(global) INTEGER. The number of rows to be operated on i.e the number of rows of the distributed submatrix sub( A ). m >= 0.
- n
-
(global) INTEGER. The number of columns to be operated on i.e the number of columns of the distributed submatrix sub( A ). n >= 0.
- alpha
-
(global) REAL for pslase2 DOUBLE PRECISION for pdlase2 COMPLEX for pclase2 DOUBLE COMPLEX for pzlase2 The constant to which the off-diagonal elements are to be set.
- beta
-
(global) REAL for pslase2 DOUBLE PRECISION for pdlase2 COMPLEX for pclase2 DOUBLE COMPLEX for pzlase2 The constant to which the diagonal elements are to be set.
- ia
-
(global) INTEGER. The row index in the global array a indicating the first row of sub( A ).
- ja
-
(global) INTEGER. The column index in the global array a indicating the first column of sub( A ).
- desca
-
(global and local) INTEGER. Array of size dlen_ . The array descriptor for the distributed matrix A .
Output Parameters
- a
-
(local) REAL for pslase2 DOUBLE PRECISION for pdlase2 COMPLEX for pclase2 DOUBLE COMPLEX for pzlase2
Pointer into the local memory to an array of size (lld_a,LOCc(ja+n-1))lld_a * LOCc ( ja + n -1) .
This array contains the local pieces of the distributed matrix sub( A ) to be set. On exit, the leading m -by- n submatrix sub( A ) is set as follows:
if uplo = ‘U’, A ( ia +i-1, ja +j-1) = alpha , 1<=i<=j-1, 1<=j<= n ,
if uplo = ‘L’, A ( ia +i-1, ja +j-1) = alpha , j+1<=i<= m , 1<=j<= n ,
otherwise, A ( ia +i-1, ja +j-1) = alpha , 1<=i<= m , 1<=j<= n , ia +i != ja +j,
and, for all uplo , A ( ia +i-1, ja +i-1) = beta , 1<=i<=min( m , n ) .