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SUBROUTINE PBDLACPZ( ICONTXT, UPLO, FORM, DIAG, M, N, A, LDA, B,
$ LDB, MINT, NINT, MEN, NEN )
*
* -- PB-BLAS routine (version 2.1) --
* University of Tennessee, Knoxville, Oak Ridge National Laboratory.
* April 28, 1996
*
* .. Scalar Arguments ..
CHARACTER*1 DIAG, FORM, UPLO
INTEGER ICONTXT, LDA, LDB, M, MEN, MINT, N, NEN, NINT
* ..
* .. Array Arguments ..
DOUBLE PRECISION A( LDA, * ), B( LDB, * )
* ..
*
* Purpose
* =======
*
* PBDLACPZ copies part of a two-dimensional upper (or lower) tri-
* angular Matrix A to another matrix B with forced zeros in the
* other part.
*
* =====================================================================
*
* .. Parameters ..
DOUBLE PRECISION ONE, ZERO
PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 )
* ..
* .. Local Scalars ..
LOGICAL NOUNIT
INTEGER I, J, JJ, JP, MN, MX
DOUBLE PRECISION DUMMY
* ..
* .. External Functions ..
LOGICAL LSAME
INTEGER ICEIL
EXTERNAL ICEIL, LSAME
* ..
* .. External Subroutines ..
EXTERNAL DCOPY, PBDMATADD, PBDVECADD
* ..
* .. Intrinsic Functions ..
INTRINSIC MIN
* ..
* .. Executable Statements ..
*
NOUNIT = LSAME( DIAG, 'N' )
JP = 0
MN = M
*
IF( LSAME( UPLO, 'U' ) ) THEN
*
IF( LSAME( FORM, 'T' ) ) THEN
*
* A is upper triangular
*
DO 20 I = 1, ICEIL( NEN, NINT )
DO 10 J = 1, MIN( N, NEN-JP )
JJ = JP + J
MX = MN + J
IF( NOUNIT ) THEN
CALL DCOPY( MX, A( 1, JJ ), 1, B( 1, JJ ), 1 )
ELSE
CALL DCOPY( MX-1, A( 1, JJ ), 1, B( 1, JJ ), 1 )
B(MX,JJ) = ONE
END IF
CALL PBDVECADD( ICONTXT, 'G', MEN-MX, ZERO, DUMMY, 1,
$ ZERO, B( MX+1, JJ ), 1 )
10 CONTINUE
MN = MN + MINT
JP = JP + NINT
20 CONTINUE
*
ELSE
*
* A is a rectangular matrix
*
DO 30 I = 1, ICEIL( NEN, NINT )
MX = MIN( N, NEN-JP )
CALL PBDMATADD( ICONTXT, 'V', MN, MX, ONE, A( 1, JP+1 ),
$ LDA, ZERO, B( 1, JP+1 ), LDB )
CALL PBDMATADD( ICONTXT, 'G', MEN-MN, MX, ZERO, DUMMY, 1,
$ ZERO, B( MN+1, JP+1 ), LDB )
MN = MN + MINT
JP = JP + NINT
30 CONTINUE
*
END IF
*
ELSE
*
IF( LSAME( FORM, 'T' ) ) THEN
*
* A is lower triangular
*
MN = M - 1
DO 50 I = 1, ICEIL( NEN, NINT )
DO 40 J = 1, MIN( N, NEN-JP )
JJ = JP + J
MX = MN + J
CALL PBDVECADD( ICONTXT, 'G', MX, ZERO, DUMMY, 1,
$ ZERO, B( 1, JJ ), 1 )
IF( NOUNIT ) THEN
CALL DCOPY( MEN-MX, A( MX+1, JJ ), 1,
$ B( MX+1, JJ ), 1 )
ELSE
B( MX+1, JJ ) = ONE
CALL DCOPY( MEN-MX-1, A( MX+2, JJ ), 1,
$ B( MX+2, JJ ), 1 )
END IF
40 CONTINUE
MN = MN + MINT
JP = JP + NINT
50 CONTINUE
*
ELSE
*
* A is a rectangular matrix
*
DO 60 I = 1, ICEIL( NEN, NINT )
MX = MIN( N, NEN-JP )
CALL PBDMATADD( ICONTXT, 'G', MN, MX, ZERO, DUMMY, 1,
$ ZERO, B( 1, JP+1 ), LDB )
CALL PBDMATADD( ICONTXT, 'V', MEN-MN, MX, ONE,
$ A( MN+1, JP+1 ), LDA, ZERO,
$ B( MN+1, JP+1), LDB )
MN = MN + MINT
JP = JP + NINT
60 CONTINUE
*
END IF
*
END IF
*
RETURN
*
* End of PBDLACPZ
*
END
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