# p?lacpy

Copies all or part of one two-dimensional array to another.

## Syntax

call pslacpy(uplo, m, n, a, ia, ja, desca, b, ib, jb, descb)

call pdlacpy(uplo, m, n, a, ia, ja, desca, b, ib, jb, descb)

call pclacpy(uplo, m, n, a, ia, ja, desca, b, ib, jb, descb)

call pzlacpy(uplo, m, n, a, ia, ja, desca, b, ib, jb, descb)

## Description

This routine copies all or part of a distributed matrix A to another distributed matrix B. No communication is performed, p?lacpy performs a local copy sub(A):= sub(B), where sub(A) denotes A(ia:ia+m-1,ja:ja+n-1) and sub(B) denotes `B(ib:ib+m-1`,jb:jb+n-1).

## Input Parameters

uplo

  (global). CHARACTER. Specifies the part of the distributed matrix sub(A) to be copied:

  = 'U': Upper triangular part; the strictly lower triangular part of sub(A) is not referenced;

  = 'L': Lower triangular part; the strictly upper triangular part of sub(A) is not referenced.

  Otherwise: all of the matrix sub(A) is copied.

m

  (global) INTEGER.

  The number of rows to be operated on, that is, the number of rows of the distributed submatrix sub(A). `(m ≥0)`.

n

  (global) INTEGER.

  The number of columns to be operated on, that is, the number of columns of the distributed submatrix sub(A). `(n≥0)`.

a

  (local).

  REAL for pslacpy

  DOUBLE PRECISION for pdlacpy

  COMPLEX for pclacpy

  COMPLEX*16 for pzlacpy.

  Pointer into the local memory to an array of DIMENSION`(lld_a, LOCc(ja+n-1))`.

  On entry, this array contains the local pieces of the distributed matrix sub(A).

ia, ja

  (global) INTEGER. The row and column indices in the global array a indicating the first row and the first column of the submatrix sub(A), respectively.

desca

  (global and local) INTEGER array, DIMENSION (dlen_). The array descriptor for the distributed matrix A.

ib, jb

  (global) INTEGER. The row and column indices in the global array B indicating the first row and the first column of sub(B) respectively.

descb

  (global and local) INTEGER array, DIMENSION (dlen_). The array descriptor for the distributed matrix A.

## Output Parameters

b

  (local).

  REAL for pslacpy

  DOUBLE PRECISION for pdlacpy

  COMPLEX for pclacpy

  COMPLEX*16 for pzlacpy.

  Pointer into the local memory to an array of DIMENSION (lld_b, LOCc(jb+n-1) ). This array contains on exit the local pieces of the distributed matrix sub( B ) set as follows:

  if `uplo = 'U'`, B(ib+i-1, jb+j-1) = A(ia+i-1, ja+j-1), 1≤i≤j, 1≤j≤n;

  if `uplo = 'L'`, B(ib+i-1, jb+j-1) = A(ia+i-1, ja+j-1),j≤i≤m, 1≤j≤n;

  otherwise, B(ib+i-1, jb+j-1) = A(ia+i-1, ja+j-1), 1≤i≤m, 1≤j≤n.

Parent topic: Auxiliary Routines