--- rpl/lapack/lapack/zlangt.f 2010/08/13 21:04:09 1.6
+++ rpl/lapack/lapack/zlangt.f 2012/12/14 12:30:31 1.11
@@ -1,9 +1,115 @@
+*> \brief \b ZLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix.
+*
+* =========== DOCUMENTATION ===========
+*
+* Online html documentation available at
+* http://www.netlib.org/lapack/explore-html/
+*
+*> \htmlonly
+*> Download ZLANGT + dependencies
+*>
+*> [TGZ]
+*>
+*> [ZIP]
+*>
+*> [TXT]
+*> \endhtmlonly
+*
+* Definition:
+* ===========
+*
+* DOUBLE PRECISION FUNCTION ZLANGT( NORM, N, DL, D, DU )
+*
+* .. Scalar Arguments ..
+* CHARACTER NORM
+* INTEGER N
+* ..
+* .. Array Arguments ..
+* COMPLEX*16 D( * ), DL( * ), DU( * )
+* ..
+*
+*
+*> \par Purpose:
+* =============
+*>
+*> \verbatim
+*>
+*> ZLANGT returns the value of the one norm, or the Frobenius norm, or
+*> the infinity norm, or the element of largest absolute value of a
+*> complex tridiagonal matrix A.
+*> \endverbatim
+*>
+*> \return ZLANGT
+*> \verbatim
+*>
+*> ZLANGT = ( 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.
+*> \endverbatim
+*
+* Arguments:
+* ==========
+*
+*> \param[in] NORM
+*> \verbatim
+*> NORM is CHARACTER*1
+*> Specifies the value to be returned in ZLANGT as described
+*> above.
+*> \endverbatim
+*>
+*> \param[in] N
+*> \verbatim
+*> N is INTEGER
+*> The order of the matrix A. N >= 0. When N = 0, ZLANGT is
+*> set to zero.
+*> \endverbatim
+*>
+*> \param[in] DL
+*> \verbatim
+*> DL is COMPLEX*16 array, dimension (N-1)
+*> The (n-1) sub-diagonal elements of A.
+*> \endverbatim
+*>
+*> \param[in] D
+*> \verbatim
+*> D is COMPLEX*16 array, dimension (N)
+*> The diagonal elements of A.
+*> \endverbatim
+*>
+*> \param[in] DU
+*> \verbatim
+*> DU is COMPLEX*16 array, dimension (N-1)
+*> The (n-1) super-diagonal elements of A.
+*> \endverbatim
+*
+* Authors:
+* ========
+*
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
+*
+*> \date September 2012
+*
+*> \ingroup complex16OTHERauxiliary
+*
+* =====================================================================
DOUBLE PRECISION FUNCTION ZLANGT( NORM, N, DL, D, DU )
*
-* -- LAPACK auxiliary routine (version 3.2) --
+* -- LAPACK auxiliary routine (version 3.4.2) --
* -- LAPACK is a software package provided by Univ. of Tennessee, --
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
-* November 2006
+* September 2012
*
* .. Scalar Arguments ..
CHARACTER NORM
@@ -13,51 +119,6 @@
COMPLEX*16 D( * ), DL( * ), DU( * )
* ..
*
-* Purpose
-* =======
-*
-* ZLANGT returns the value of the one norm, or the Frobenius norm, or
-* the infinity norm, or the element of largest absolute value of a
-* complex tridiagonal matrix A.
-*
-* Description
-* ===========
-*
-* ZLANGT returns the value
-*
-* ZLANGT = ( 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 ZLANGT as described
-* above.
-*
-* N (input) INTEGER
-* The order of the matrix A. N >= 0. When N = 0, ZLANGT is
-* set to zero.
-*
-* DL (input) COMPLEX*16 array, dimension (N-1)
-* The (n-1) sub-diagonal elements of A.
-*
-* D (input) COMPLEX*16 array, dimension (N)
-* The diagonal elements of A.
-*
-* DU (input) COMPLEX*16 array, dimension (N-1)
-* The (n-1) super-diagonal elements of A.
-*
* =====================================================================
*
* .. Parameters ..
@@ -66,17 +127,17 @@
* ..
* .. Local Scalars ..
INTEGER I
- DOUBLE PRECISION ANORM, SCALE, SUM
+ DOUBLE PRECISION ANORM, SCALE, SUM, TEMP
* ..
* .. External Functions ..
- LOGICAL LSAME
- EXTERNAL LSAME
+ LOGICAL LSAME, DISNAN
+ EXTERNAL LSAME, DISNAN
* ..
* .. External Subroutines ..
EXTERNAL ZLASSQ
* ..
* .. Intrinsic Functions ..
- INTRINSIC ABS, MAX, SQRT
+ INTRINSIC ABS, SQRT
* ..
* .. Executable Statements ..
*
@@ -88,9 +149,12 @@
*
ANORM = ABS( D( N ) )
DO 10 I = 1, N - 1
- ANORM = MAX( ANORM, ABS( DL( I ) ) )
- ANORM = MAX( ANORM, ABS( D( I ) ) )
- ANORM = MAX( ANORM, ABS( DU( I ) ) )
+ IF( ANORM.LT.ABS( DL( I ) ) .OR. DISNAN( ABS( DL( I ) ) ) )
+ $ ANORM = ABS(DL(I))
+ IF( ANORM.LT.ABS( D( I ) ) .OR. DISNAN( ABS( D( I ) ) ) )
+ $ ANORM = ABS(D(I))
+ IF( ANORM.LT.ABS( DU( I ) ) .OR. DISNAN (ABS( DU( I ) ) ) )
+ $ ANORM = ABS(DU(I))
10 CONTINUE
ELSE IF( LSAME( NORM, 'O' ) .OR. NORM.EQ.'1' ) THEN
*
@@ -99,11 +163,12 @@
IF( N.EQ.1 ) THEN
ANORM = ABS( D( 1 ) )
ELSE
- ANORM = MAX( ABS( D( 1 ) )+ABS( DL( 1 ) ),
- $ ABS( D( N ) )+ABS( DU( N-1 ) ) )
+ ANORM = ABS( D( 1 ) )+ABS( DL( 1 ) )
+ TEMP = ABS( D( N ) )+ABS( DU( N-1 ) )
+ IF( ANORM .LT. TEMP .OR. DISNAN( TEMP ) ) ANORM = TEMP
DO 20 I = 2, N - 1
- ANORM = MAX( ANORM, ABS( D( I ) )+ABS( DL( I ) )+
- $ ABS( DU( I-1 ) ) )
+ TEMP = ABS( D( I ) )+ABS( DL( I ) )+ABS( DU( I-1 ) )
+ IF( ANORM .LT. TEMP .OR. DISNAN( TEMP ) ) ANORM = TEMP
20 CONTINUE
END IF
ELSE IF( LSAME( NORM, 'I' ) ) THEN
@@ -113,11 +178,12 @@
IF( N.EQ.1 ) THEN
ANORM = ABS( D( 1 ) )
ELSE
- ANORM = MAX( ABS( D( 1 ) )+ABS( DU( 1 ) ),
- $ ABS( D( N ) )+ABS( DL( N-1 ) ) )
+ ANORM = ABS( D( 1 ) )+ABS( DU( 1 ) )
+ TEMP = ABS( D( N ) )+ABS( DL( N-1 ) )
+ IF( ANORM .LT. TEMP .OR. DISNAN( TEMP ) ) ANORM = TEMP
DO 30 I = 2, N - 1
- ANORM = MAX( ANORM, ABS( D( I ) )+ABS( DU( I ) )+
- $ ABS( DL( I-1 ) ) )
+ TEMP = ABS( D( I ) )+ABS( DU( I ) )+ABS( DL( I-1 ) )
+ IF( ANORM .LT. TEMP .OR. DISNAN( TEMP ) ) ANORM = TEMP
30 CONTINUE
END IF
ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN