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Diffstat (limited to '2.3-1/src/fortran/lapack/dlantr.f')
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diff --git a/2.3-1/src/fortran/lapack/dlantr.f b/2.3-1/src/fortran/lapack/dlantr.f new file mode 100644 index 00000000..92debd3d --- /dev/null +++ b/2.3-1/src/fortran/lapack/dlantr.f @@ -0,0 +1,276 @@ + DOUBLE PRECISION FUNCTION DLANTR( NORM, UPLO, DIAG, M, N, A, LDA, + $ WORK ) +* +* -- LAPACK auxiliary routine (version 3.1) -- +* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. +* November 2006 +* +* .. Scalar Arguments .. + CHARACTER DIAG, NORM, UPLO + INTEGER LDA, M, N +* .. +* .. Array Arguments .. + DOUBLE PRECISION A( LDA, * ), WORK( * ) +* .. +* +* Purpose +* ======= +* +* DLANTR returns the value of the one norm, or the Frobenius norm, or +* the infinity norm, or the element of largest absolute value of a +* trapezoidal or triangular matrix A. +* +* Description +* =========== +* +* DLANTR returns the value +* +* DLANTR = ( max(abs(A(i,j))), NORM = 'M' or 'm' +* ( +* ( norm1(A), NORM = '1', 'O' or 'o' +* ( +* ( normI(A), NORM = 'I' or 'i' +* ( +* ( normF(A), NORM = 'F', 'f', 'E' or 'e' +* +* where norm1 denotes the one norm of a matrix (maximum column sum), +* normI denotes the infinity norm of a matrix (maximum row sum) and +* normF denotes the Frobenius norm of a matrix (square root of sum of +* squares). Note that max(abs(A(i,j))) is not a consistent matrix norm. +* +* Arguments +* ========= +* +* NORM (input) CHARACTER*1 +* Specifies the value to be returned in DLANTR as described +* above. +* +* UPLO (input) CHARACTER*1 +* Specifies whether the matrix A is upper or lower trapezoidal. +* = 'U': Upper trapezoidal +* = 'L': Lower trapezoidal +* Note that A is triangular instead of trapezoidal if M = N. +* +* DIAG (input) CHARACTER*1 +* Specifies whether or not the matrix A has unit diagonal. +* = 'N': Non-unit diagonal +* = 'U': Unit diagonal +* +* M (input) INTEGER +* The number of rows of the matrix A. M >= 0, and if +* UPLO = 'U', M <= N. When M = 0, DLANTR is set to zero. +* +* N (input) INTEGER +* The number of columns of the matrix A. N >= 0, and if +* UPLO = 'L', N <= M. When N = 0, DLANTR is set to zero. +* +* A (input) DOUBLE PRECISION array, dimension (LDA,N) +* The trapezoidal matrix A (A is triangular if M = N). +* If UPLO = 'U', the leading m by n upper trapezoidal part of +* the array A contains the upper trapezoidal matrix, and the +* strictly lower triangular part of A is not referenced. +* If UPLO = 'L', the leading m by n lower trapezoidal part of +* the array A contains the lower trapezoidal matrix, and the +* strictly upper triangular part of A is not referenced. Note +* that when DIAG = 'U', the diagonal elements of A are not +* referenced and are assumed to be one. +* +* LDA (input) INTEGER +* The leading dimension of the array A. LDA >= max(M,1). +* +* WORK (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)), +* where LWORK >= M when NORM = 'I'; otherwise, WORK is not +* referenced. +* +* ===================================================================== +* +* .. Parameters .. + DOUBLE PRECISION ONE, ZERO + PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 ) +* .. +* .. Local Scalars .. + LOGICAL UDIAG + INTEGER I, J + DOUBLE PRECISION SCALE, SUM, VALUE +* .. +* .. External Subroutines .. + EXTERNAL DLASSQ +* .. +* .. External Functions .. + LOGICAL LSAME + EXTERNAL LSAME +* .. +* .. Intrinsic Functions .. + INTRINSIC ABS, MAX, MIN, SQRT +* .. +* .. Executable Statements .. +* + IF( MIN( M, N ).EQ.0 ) THEN + VALUE = ZERO + ELSE IF( LSAME( NORM, 'M' ) ) THEN +* +* Find max(abs(A(i,j))). +* + IF( LSAME( DIAG, 'U' ) ) THEN + VALUE = ONE + IF( LSAME( UPLO, 'U' ) ) THEN + DO 20 J = 1, N + DO 10 I = 1, MIN( M, J-1 ) + VALUE = MAX( VALUE, ABS( A( I, J ) ) ) + 10 CONTINUE + 20 CONTINUE + ELSE + DO 40 J = 1, N + DO 30 I = J + 1, M + VALUE = MAX( VALUE, ABS( A( I, J ) ) ) + 30 CONTINUE + 40 CONTINUE + END IF + ELSE + VALUE = ZERO + IF( LSAME( UPLO, 'U' ) ) THEN + DO 60 J = 1, N + DO 50 I = 1, MIN( M, J ) + VALUE = MAX( VALUE, ABS( A( I, J ) ) ) + 50 CONTINUE + 60 CONTINUE + ELSE + DO 80 J = 1, N + DO 70 I = J, M + VALUE = MAX( VALUE, ABS( A( I, J ) ) ) + 70 CONTINUE + 80 CONTINUE + END IF + END IF + ELSE IF( ( LSAME( NORM, 'O' ) ) .OR. ( NORM.EQ.'1' ) ) THEN +* +* Find norm1(A). +* + VALUE = ZERO + UDIAG = LSAME( DIAG, 'U' ) + IF( LSAME( UPLO, 'U' ) ) THEN + DO 110 J = 1, N + IF( ( UDIAG ) .AND. ( J.LE.M ) ) THEN + SUM = ONE + DO 90 I = 1, J - 1 + SUM = SUM + ABS( A( I, J ) ) + 90 CONTINUE + ELSE + SUM = ZERO + DO 100 I = 1, MIN( M, J ) + SUM = SUM + ABS( A( I, J ) ) + 100 CONTINUE + END IF + VALUE = MAX( VALUE, SUM ) + 110 CONTINUE + ELSE + DO 140 J = 1, N + IF( UDIAG ) THEN + SUM = ONE + DO 120 I = J + 1, M + SUM = SUM + ABS( A( I, J ) ) + 120 CONTINUE + ELSE + SUM = ZERO + DO 130 I = J, M + SUM = SUM + ABS( A( I, J ) ) + 130 CONTINUE + END IF + VALUE = MAX( VALUE, SUM ) + 140 CONTINUE + END IF + ELSE IF( LSAME( NORM, 'I' ) ) THEN +* +* Find normI(A). +* + IF( LSAME( UPLO, 'U' ) ) THEN + IF( LSAME( DIAG, 'U' ) ) THEN + DO 150 I = 1, M + WORK( I ) = ONE + 150 CONTINUE + DO 170 J = 1, N + DO 160 I = 1, MIN( M, J-1 ) + WORK( I ) = WORK( I ) + ABS( A( I, J ) ) + 160 CONTINUE + 170 CONTINUE + ELSE + DO 180 I = 1, M + WORK( I ) = ZERO + 180 CONTINUE + DO 200 J = 1, N + DO 190 I = 1, MIN( M, J ) + WORK( I ) = WORK( I ) + ABS( A( I, J ) ) + 190 CONTINUE + 200 CONTINUE + END IF + ELSE + IF( LSAME( DIAG, 'U' ) ) THEN + DO 210 I = 1, N + WORK( I ) = ONE + 210 CONTINUE + DO 220 I = N + 1, M + WORK( I ) = ZERO + 220 CONTINUE + DO 240 J = 1, N + DO 230 I = J + 1, M + WORK( I ) = WORK( I ) + ABS( A( I, J ) ) + 230 CONTINUE + 240 CONTINUE + ELSE + DO 250 I = 1, M + WORK( I ) = ZERO + 250 CONTINUE + DO 270 J = 1, N + DO 260 I = J, M + WORK( I ) = WORK( I ) + ABS( A( I, J ) ) + 260 CONTINUE + 270 CONTINUE + END IF + END IF + VALUE = ZERO + DO 280 I = 1, M + VALUE = MAX( VALUE, WORK( I ) ) + 280 CONTINUE + ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN +* +* Find normF(A). +* + IF( LSAME( UPLO, 'U' ) ) THEN + IF( LSAME( DIAG, 'U' ) ) THEN + SCALE = ONE + SUM = MIN( M, N ) + DO 290 J = 2, N + CALL DLASSQ( MIN( M, J-1 ), A( 1, J ), 1, SCALE, SUM ) + 290 CONTINUE + ELSE + SCALE = ZERO + SUM = ONE + DO 300 J = 1, N + CALL DLASSQ( MIN( M, J ), A( 1, J ), 1, SCALE, SUM ) + 300 CONTINUE + END IF + ELSE + IF( LSAME( DIAG, 'U' ) ) THEN + SCALE = ONE + SUM = MIN( M, N ) + DO 310 J = 1, N + CALL DLASSQ( M-J, A( MIN( M, J+1 ), J ), 1, SCALE, + $ SUM ) + 310 CONTINUE + ELSE + SCALE = ZERO + SUM = ONE + DO 320 J = 1, N + CALL DLASSQ( M-J+1, A( J, J ), 1, SCALE, SUM ) + 320 CONTINUE + END IF + END IF + VALUE = SCALE*SQRT( SUM ) + END IF +* + DLANTR = VALUE + RETURN +* +* End of DLANTR +* + END |