LAPACK  3.4.1
LAPACK: Linear Algebra PACKage
dlatb5.f
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00001 *> \brief \b DLATB5
00002 *
00003 *  =========== DOCUMENTATION ===========
00004 *
00005 * Online html documentation available at 
00006 *            http://www.netlib.org/lapack/explore-html/ 
00007 *
00008 *  Definition:
00009 *  ===========
00010 *
00011 *       SUBROUTINE DLATB5( PATH, IMAT, N, TYPE, KL, KU, ANORM, MODE,
00012 *                          CNDNUM, DIST )
00013 * 
00014 *       .. Scalar Arguments ..
00015 *       DOUBLE PRECISION   ANORM, CNDNUM
00016 *       INTEGER            IMAT, KL, KU, MODE, N
00017 *       CHARACTER          DIST, TYPE
00018 *       CHARACTER*3        PATH
00019 *       ..
00020 *  
00021 *
00022 *> \par Purpose:
00023 *  =============
00024 *>
00025 *> \verbatim
00026 *>
00027 *> DLATB5 sets parameters for the matrix generator based on the type
00028 *> of matrix to be generated.
00029 *> \endverbatim
00030 *
00031 *  Arguments:
00032 *  ==========
00033 *
00034 *> \param[in] PATH
00035 *> \verbatim
00036 *>          PATH is CHARACTER*3
00037 *>          The LAPACK path name.
00038 *> \endverbatim
00039 *>
00040 *> \param[in] IMAT
00041 *> \verbatim
00042 *>          IMAT is INTEGER
00043 *>          An integer key describing which matrix to generate for this
00044 *>          path.
00045 *> \endverbatim
00046 *>
00047 *> \param[in] N
00048 *> \verbatim
00049 *>          N is INTEGER
00050 *>          The number of rows and columns in the matrix to be generated.
00051 *> \endverbatim
00052 *>
00053 *> \param[out] TYPE
00054 *> \verbatim
00055 *>          TYPE is CHARACTER*1
00056 *>          The type of the matrix to be generated:
00057 *>          = 'S':  symmetric matrix
00058 *>          = 'P':  symmetric positive (semi)definite matrix
00059 *>          = 'N':  nonsymmetric matrix
00060 *> \endverbatim
00061 *>
00062 *> \param[out] KL
00063 *> \verbatim
00064 *>          KL is INTEGER
00065 *>          The lower band width of the matrix to be generated.
00066 *> \endverbatim
00067 *>
00068 *> \param[out] KU
00069 *> \verbatim
00070 *>          KU is INTEGER
00071 *>          The upper band width of the matrix to be generated.
00072 *> \endverbatim
00073 *>
00074 *> \param[out] ANORM
00075 *> \verbatim
00076 *>          ANORM is DOUBLE PRECISION
00077 *>          The desired norm of the matrix to be generated.  The diagonal
00078 *>          matrix of singular values or eigenvalues is scaled by this
00079 *>          value.
00080 *> \endverbatim
00081 *>
00082 *> \param[out] MODE
00083 *> \verbatim
00084 *>          MODE is INTEGER
00085 *>          A key indicating how to choose the vector of eigenvalues.
00086 *> \endverbatim
00087 *>
00088 *> \param[out] CNDNUM
00089 *> \verbatim
00090 *>          CNDNUM is DOUBLE PRECISION
00091 *>          The desired condition number.
00092 *> \endverbatim
00093 *>
00094 *> \param[out] DIST
00095 *> \verbatim
00096 *>          DIST is CHARACTER*1
00097 *>          The type of distribution to be used by the random number
00098 *>          generator.
00099 *> \endverbatim
00100 *
00101 *  Authors:
00102 *  ========
00103 *
00104 *> \author Univ. of Tennessee 
00105 *> \author Univ. of California Berkeley 
00106 *> \author Univ. of Colorado Denver 
00107 *> \author NAG Ltd. 
00108 *
00109 *> \date November 2011
00110 *
00111 *> \ingroup double_lin
00112 *
00113 *  =====================================================================
00114       SUBROUTINE DLATB5( PATH, IMAT, N, TYPE, KL, KU, ANORM, MODE,
00115      $                   CNDNUM, DIST )
00116 *
00117 *  -- LAPACK test routine (version 3.4.0) --
00118 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
00119 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
00120 *     November 2011
00121 *
00122 *     .. Scalar Arguments ..
00123       DOUBLE PRECISION   ANORM, CNDNUM
00124       INTEGER            IMAT, KL, KU, MODE, N
00125       CHARACTER          DIST, TYPE
00126       CHARACTER*3        PATH
00127 *     ..
00128 *
00129 *  =====================================================================
00130 *
00131 *     .. Parameters ..
00132       DOUBLE PRECISION   SHRINK, TENTH
00133       PARAMETER          ( SHRINK = 0.25D0, TENTH = 0.1D+0 )
00134       DOUBLE PRECISION   ONE
00135       PARAMETER          ( ONE = 1.0D+0 )
00136       DOUBLE PRECISION   TWO
00137       PARAMETER          ( TWO = 2.0D+0 )
00138 *     ..
00139 *     .. Local Scalars ..
00140       DOUBLE PRECISION   BADC1, BADC2, EPS, LARGE, SMALL
00141       LOGICAL            FIRST
00142       CHARACTER*2        C2
00143 *     ..
00144 *     .. External Functions ..
00145       DOUBLE PRECISION   DLAMCH
00146       EXTERNAL           DLAMCH
00147 *     ..
00148 *     .. Intrinsic Functions ..
00149       INTRINSIC          MAX, SQRT
00150 *     ..
00151 *     .. External Subroutines ..
00152       EXTERNAL           DLABAD
00153 *     ..
00154 *     .. Save statement ..
00155       SAVE               EPS, SMALL, LARGE, BADC1, BADC2, FIRST
00156 *     ..
00157 *     .. Data statements ..
00158       DATA               FIRST / .TRUE. /
00159 *     ..
00160 *     .. Executable Statements ..
00161 *
00162 *     Set some constants for use in the subroutine.
00163 *
00164       IF( FIRST ) THEN
00165          FIRST = .FALSE.
00166          EPS = DLAMCH( 'Precision' )
00167          BADC2 = TENTH / EPS
00168          BADC1 = SQRT( BADC2 )
00169          SMALL = DLAMCH( 'Safe minimum' )
00170          LARGE = ONE / SMALL
00171 *
00172 *        If it looks like we're on a Cray, take the square root of
00173 *        SMALL and LARGE to avoid overflow and underflow problems.
00174 *
00175          CALL DLABAD( SMALL, LARGE )
00176          SMALL = SHRINK*( SMALL / EPS )
00177          LARGE = ONE / SMALL
00178       END IF
00179 *
00180       C2 = PATH( 2: 3 )
00181 *
00182 *     Set some parameters
00183 *
00184       DIST = 'S'
00185       MODE = 3
00186 *
00187 *     Set TYPE, the type of matrix to be generated.
00188 *
00189       TYPE = C2( 1: 1 )
00190 *
00191 *     Set the lower and upper bandwidths.
00192 *
00193       IF( IMAT.EQ.1 ) THEN
00194          KL = 0
00195       ELSE
00196          KL = MAX( N-1, 0 )
00197       END IF
00198       KU = KL
00199 *
00200 *     Set the condition number and norm.etc
00201 *
00202       IF( IMAT.EQ.3 ) THEN
00203          CNDNUM = 1.0D12
00204          MODE = 2
00205       ELSE IF( IMAT.EQ.4 ) THEN
00206          CNDNUM = 1.0D12
00207          MODE = 1
00208       ELSE IF( IMAT.EQ.5 ) THEN
00209          CNDNUM = 1.0D12
00210          MODE = 3
00211       ELSE IF( IMAT.EQ.6 ) THEN
00212          CNDNUM = BADC1
00213       ELSE IF( IMAT.EQ.7 ) THEN
00214          CNDNUM = BADC2
00215       ELSE
00216          CNDNUM = TWO
00217       END IF
00218 *
00219       IF( IMAT.EQ.8 ) THEN
00220          ANORM = SMALL
00221       ELSE IF( IMAT.EQ.9 ) THEN
00222          ANORM = LARGE
00223       ELSE
00224          ANORM = ONE
00225       END IF
00226 *
00227       IF( N.LE.1 )
00228      $   CNDNUM = ONE
00229 *
00230       RETURN
00231 *
00232 *     End of DLATB5
00233 *
00234       END
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