PZDRSCL(l) | LAPACK auxiliary routine (version 1.5) | PZDRSCL(l) |
NAME¶
PZDRSCL - multiplie an N-element complex distributed vector sub( X ) by the real scalar 1/aSYNOPSIS¶
- SUBROUTINE PZDRSCL(
- N, SA, SX, IX, JX, DESCX, INCX )
PURPOSE¶
PZDRSCL multiplies an N-element complex distributed vector sub( X ) by the real scalar 1/a. This is done without overflow or underflow as long as the final sub( X )/a does not overflow or underflow.X(IX:IX,JX:JX+N-1), if INCX = M_X. Notes
DT_A = 1.
the BLACS process grid A is distribu-
ted over. The context itself is glo-
bal, but the handle (the integer
value) may vary.
array A.
array A.
te the rows of the array.
te the columns of the array. RSRC_A (global) descA[ RSRC_ ] The process row over which the first
row of the array A is distributed. CSRC_A (global) descA[ CSRC_ ] The process column over which the
first column of the array A is
distributed.
array. LLD_A >= MAX(1,LOCr(M_A)). Let K be the number of rows or columns of a distributed matrix, and assume that its process grid has dimension p x q.
LOCr( M ) = NUMROC( M, MB_A, MYROW, RSRC_A, NPROW ),
LOCc( N ) = NUMROC( N, NB_A, MYCOL, CSRC_A, NPCOL ). An upper bound for these quantities may be computed by:
LOCr( M ) <= ceil( ceil(M/MB_A)/NPROW )*MB_A
LOCc( N ) <= ceil( ceil(N/NB_A)/NPCOL )*NB_A
ARGUMENTS¶
- N (global input) pointer to INTEGER
- The number of components of the distributed vector sub( X ). N >= 0.
- SA (global input) DOUBLE PRECISION
- The scalar a which is used to divide each component of sub( X ). SA must be >= 0, or the subroutine will divide by zero.
- SX (local input/local output) COMPLEX*16 array
- containing the local pieces of a distributed matrix of dimension of at least ( (JX-1)*M_X + IX + ( N - 1 )*abs( INCX ) ) This array contains the entries of the distributed vector sub( X ).
- IX (global input) pointer to INTEGER
- The global row index of the submatrix of the distributed matrix X to operate on.
- JX (global input) pointer to INTEGER
- The global column index of the submatrix of the distributed matrix X to operate on.
- DESCX (global and local input) INTEGER array of dimension 8.
- The array descriptor of the distributed matrix X.
- INCX (global input) pointer to INTEGER
- The global increment for the elements of X. Only two values of INCX are supported in this version, namely 1 and M_X.
12 May 1997 | LAPACK version 1.5 |