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Diffstat (limited to 'SRC/dlapmt.f')
-rw-r--r-- | SRC/dlapmt.f | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/SRC/dlapmt.f b/SRC/dlapmt.f new file mode 100644 index 00000000..325774c0 --- /dev/null +++ b/SRC/dlapmt.f @@ -0,0 +1,136 @@ + SUBROUTINE DLAPMT( FORWRD, M, N, X, LDX, K ) +* +* -- LAPACK auxiliary routine (version 3.1) -- +* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. +* November 2006 +* +* .. Scalar Arguments .. + LOGICAL FORWRD + INTEGER LDX, M, N +* .. +* .. Array Arguments .. + INTEGER K( * ) + DOUBLE PRECISION X( LDX, * ) +* .. +* +* Purpose +* ======= +* +* DLAPMT rearranges the columns of the M by N matrix X as specified +* by the permutation K(1),K(2),...,K(N) of the integers 1,...,N. +* If FORWRD = .TRUE., forward permutation: +* +* X(*,K(J)) is moved X(*,J) for J = 1,2,...,N. +* +* If FORWRD = .FALSE., backward permutation: +* +* X(*,J) is moved to X(*,K(J)) for J = 1,2,...,N. +* +* Arguments +* ========= +* +* FORWRD (input) LOGICAL +* = .TRUE., forward permutation +* = .FALSE., backward permutation +* +* M (input) INTEGER +* The number of rows of the matrix X. M >= 0. +* +* N (input) INTEGER +* The number of columns of the matrix X. N >= 0. +* +* X (input/output) DOUBLE PRECISION array, dimension (LDX,N) +* On entry, the M by N matrix X. +* On exit, X contains the permuted matrix X. +* +* LDX (input) INTEGER +* The leading dimension of the array X, LDX >= MAX(1,M). +* +* K (input/output) INTEGER array, dimension (N) +* On entry, K contains the permutation vector. K is used as +* internal workspace, but reset to its original value on +* output. +* +* ===================================================================== +* +* .. Local Scalars .. + INTEGER I, II, IN, J + DOUBLE PRECISION TEMP +* .. +* .. Executable Statements .. +* + IF( N.LE.1 ) + $ RETURN +* + DO 10 I = 1, N + K( I ) = -K( I ) + 10 CONTINUE +* + IF( FORWRD ) THEN +* +* Forward permutation +* + DO 50 I = 1, N +* + IF( K( I ).GT.0 ) + $ GO TO 40 +* + J = I + K( J ) = -K( J ) + IN = K( J ) +* + 20 CONTINUE + IF( K( IN ).GT.0 ) + $ GO TO 40 +* + DO 30 II = 1, M + TEMP = X( II, J ) + X( II, J ) = X( II, IN ) + X( II, IN ) = TEMP + 30 CONTINUE +* + K( IN ) = -K( IN ) + J = IN + IN = K( IN ) + GO TO 20 +* + 40 CONTINUE +* + 50 CONTINUE +* + ELSE +* +* Backward permutation +* + DO 90 I = 1, N +* + IF( K( I ).GT.0 ) + $ GO TO 80 +* + K( I ) = -K( I ) + J = K( I ) + 60 CONTINUE + IF( J.EQ.I ) + $ GO TO 80 +* + DO 70 II = 1, M + TEMP = X( II, I ) + X( II, I ) = X( II, J ) + X( II, J ) = TEMP + 70 CONTINUE +* + K( J ) = -K( J ) + J = K( J ) + GO TO 60 +* + 80 CONTINUE +* + 90 CONTINUE +* + END IF +* + RETURN +* +* End of DLAPMT +* + END |