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annotate libcruft/lapack/sgebal.f @ 9607:1be3c73ed7b5

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reuse temporary arrays in nested expressions
author Jaroslav Hajek <highegg@gmail.com>
date Thu, 03 Sep 2009 08:48:51 +0200
parents 82be108cc558
children
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7789
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1 SUBROUTINE SGEBAL( JOB, N, A, LDA, ILO, IHI, SCALE, INFO )
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2 *
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3 * -- LAPACK routine (version 3.1) --
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4 * Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
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5 * November 2006
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6 *
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7 * .. Scalar Arguments ..
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8 CHARACTER JOB
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9 INTEGER IHI, ILO, INFO, LDA, N
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10 * ..
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11 * .. Array Arguments ..
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12 REAL A( LDA, * ), SCALE( * )
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13 * ..
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14 *
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15 * Purpose
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16 * =======
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17 *
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18 * SGEBAL balances a general real matrix A. This involves, first,
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19 * permuting A by a similarity transformation to isolate eigenvalues
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20 * in the first 1 to ILO-1 and last IHI+1 to N elements on the
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21 * diagonal; and second, applying a diagonal similarity transformation
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22 * to rows and columns ILO to IHI to make the rows and columns as
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23 * close in norm as possible. Both steps are optional.
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24 *
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25 * Balancing may reduce the 1-norm of the matrix, and improve the
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26 * accuracy of the computed eigenvalues and/or eigenvectors.
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27 *
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28 * Arguments
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29 * =========
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30 *
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31 * JOB (input) CHARACTER*1
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32 * Specifies the operations to be performed on A:
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33 * = 'N': none: simply set ILO = 1, IHI = N, SCALE(I) = 1.0
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34 * for i = 1,...,N;
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35 * = 'P': permute only;
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36 * = 'S': scale only;
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37 * = 'B': both permute and scale.
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38 *
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39 * N (input) INTEGER
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40 * The order of the matrix A. N >= 0.
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41 *
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42 * A (input/output) REAL array, dimension (LDA,N)
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43 * On entry, the input matrix A.
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44 * On exit, A is overwritten by the balanced matrix.
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45 * If JOB = 'N', A is not referenced.
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46 * See Further Details.
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47 *
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48 * LDA (input) INTEGER
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49 * The leading dimension of the array A. LDA >= max(1,N).
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50 *
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51 * ILO (output) INTEGER
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52 * IHI (output) INTEGER
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53 * ILO and IHI are set to integers such that on exit
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54 * A(i,j) = 0 if i > j and j = 1,...,ILO-1 or I = IHI+1,...,N.
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55 * If JOB = 'N' or 'S', ILO = 1 and IHI = N.
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56 *
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57 * SCALE (output) REAL array, dimension (N)
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58 * Details of the permutations and scaling factors applied to
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59 * A. If P(j) is the index of the row and column interchanged
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60 * with row and column j and D(j) is the scaling factor
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61 * applied to row and column j, then
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62 * SCALE(j) = P(j) for j = 1,...,ILO-1
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63 * = D(j) for j = ILO,...,IHI
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64 * = P(j) for j = IHI+1,...,N.
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65 * The order in which the interchanges are made is N to IHI+1,
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66 * then 1 to ILO-1.
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67 *
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68 * INFO (output) INTEGER
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69 * = 0: successful exit.
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70 * < 0: if INFO = -i, the i-th argument had an illegal value.
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71 *
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72 * Further Details
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73 * ===============
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74 *
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75 * The permutations consist of row and column interchanges which put
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76 * the matrix in the form
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77 *
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78 * ( T1 X Y )
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79 * P A P = ( 0 B Z )
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80 * ( 0 0 T2 )
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81 *
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82 * where T1 and T2 are upper triangular matrices whose eigenvalues lie
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83 * along the diagonal. The column indices ILO and IHI mark the starting
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84 * and ending columns of the submatrix B. Balancing consists of applying
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85 * a diagonal similarity transformation inv(D) * B * D to make the
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86 * 1-norms of each row of B and its corresponding column nearly equal.
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87 * The output matrix is
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88 *
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89 * ( T1 X*D Y )
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90 * ( 0 inv(D)*B*D inv(D)*Z ).
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91 * ( 0 0 T2 )
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92 *
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93 * Information about the permutations P and the diagonal matrix D is
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94 * returned in the vector SCALE.
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95 *
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96 * This subroutine is based on the EISPACK routine BALANC.
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97 *
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98 * Modified by Tzu-Yi Chen, Computer Science Division, University of
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99 * California at Berkeley, USA
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100 *
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101 * =====================================================================
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102 *
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103 * .. Parameters ..
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104 REAL ZERO, ONE
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105 PARAMETER ( ZERO = 0.0E+0, ONE = 1.0E+0 )
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106 REAL SCLFAC
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107 PARAMETER ( SCLFAC = 2.0E+0 )
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108 REAL FACTOR
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109 PARAMETER ( FACTOR = 0.95E+0 )
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110 * ..
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111 * .. Local Scalars ..
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112 LOGICAL NOCONV
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113 INTEGER I, ICA, IEXC, IRA, J, K, L, M
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114 REAL C, CA, F, G, R, RA, S, SFMAX1, SFMAX2, SFMIN1,
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115 $ SFMIN2
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116 * ..
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117 * .. External Functions ..
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118 LOGICAL LSAME
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119 INTEGER ISAMAX
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120 REAL SLAMCH
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121 EXTERNAL LSAME, ISAMAX, SLAMCH
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122 * ..
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123 * .. External Subroutines ..
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124 EXTERNAL SSCAL, SSWAP, XERBLA
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125 * ..
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126 * .. Intrinsic Functions ..
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127 INTRINSIC ABS, MAX, MIN
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128 * ..
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129 * .. Executable Statements ..
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130 *
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131 * Test the input parameters
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132 *
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133 INFO = 0
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134 IF( .NOT.LSAME( JOB, 'N' ) .AND. .NOT.LSAME( JOB, 'P' ) .AND.
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135 $ .NOT.LSAME( JOB, 'S' ) .AND. .NOT.LSAME( JOB, 'B' ) ) THEN
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136 INFO = -1
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137 ELSE IF( N.LT.0 ) THEN
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138 INFO = -2
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139 ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
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140 INFO = -4
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141 END IF
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142 IF( INFO.NE.0 ) THEN
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143 CALL XERBLA( 'SGEBAL', -INFO )
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144 RETURN
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145 END IF
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146 *
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147 K = 1
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148 L = N
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149 *
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150 IF( N.EQ.0 )
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151 $ GO TO 210
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152 *
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153 IF( LSAME( JOB, 'N' ) ) THEN
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154 DO 10 I = 1, N
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155 SCALE( I ) = ONE
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156 10 CONTINUE
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157 GO TO 210
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158 END IF
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159 *
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160 IF( LSAME( JOB, 'S' ) )
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161 $ GO TO 120
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162 *
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163 * Permutation to isolate eigenvalues if possible
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164 *
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165 GO TO 50
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166 *
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David Bateman <dbateman@free.fr>
parents:
diff changeset
167 * Row and column exchange.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
168 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
169 20 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
170 SCALE( M ) = J
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
171 IF( J.EQ.M )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
172 $ GO TO 30
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
173 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
174 CALL SSWAP( L, A( 1, J ), 1, A( 1, M ), 1 )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
175 CALL SSWAP( N-K+1, A( J, K ), LDA, A( M, K ), LDA )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
176 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
177 30 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
178 GO TO ( 40, 80 )IEXC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
179 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
180 * Search for rows isolating an eigenvalue and push them down.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
181 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
182 40 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
183 IF( L.EQ.1 )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
184 $ GO TO 210
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
185 L = L - 1
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
186 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
187 50 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
188 DO 70 J = L, 1, -1
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
189 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
190 DO 60 I = 1, L
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
191 IF( I.EQ.J )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
192 $ GO TO 60
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
193 IF( A( J, I ).NE.ZERO )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
194 $ GO TO 70
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
195 60 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
196 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
197 M = L
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
198 IEXC = 1
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
199 GO TO 20
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
200 70 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
201 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
202 GO TO 90
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
203 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
204 * Search for columns isolating an eigenvalue and push them left.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
205 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
206 80 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
207 K = K + 1
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
208 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
209 90 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
210 DO 110 J = K, L
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
211 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
212 DO 100 I = K, L
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
213 IF( I.EQ.J )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
214 $ GO TO 100
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
215 IF( A( I, J ).NE.ZERO )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
216 $ GO TO 110
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
217 100 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
218 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
219 M = K
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
220 IEXC = 2
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
221 GO TO 20
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
222 110 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
223 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
224 120 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
225 DO 130 I = K, L
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
226 SCALE( I ) = ONE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
227 130 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
228 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
229 IF( LSAME( JOB, 'P' ) )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
230 $ GO TO 210
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
231 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
232 * Balance the submatrix in rows K to L.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
233 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
234 * Iterative loop for norm reduction
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
235 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
236 SFMIN1 = SLAMCH( 'S' ) / SLAMCH( 'P' )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
237 SFMAX1 = ONE / SFMIN1
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
238 SFMIN2 = SFMIN1*SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
239 SFMAX2 = ONE / SFMIN2
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
240 140 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
241 NOCONV = .FALSE.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
242 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
243 DO 200 I = K, L
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
244 C = ZERO
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
245 R = ZERO
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
246 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
247 DO 150 J = K, L
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
248 IF( J.EQ.I )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
249 $ GO TO 150
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
250 C = C + ABS( A( J, I ) )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
251 R = R + ABS( A( I, J ) )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
252 150 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
253 ICA = ISAMAX( L, A( 1, I ), 1 )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
254 CA = ABS( A( ICA, I ) )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
255 IRA = ISAMAX( N-K+1, A( I, K ), LDA )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
256 RA = ABS( A( I, IRA+K-1 ) )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
257 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
258 * Guard against zero C or R due to underflow.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
259 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
260 IF( C.EQ.ZERO .OR. R.EQ.ZERO )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
261 $ GO TO 200
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
262 G = R / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
263 F = ONE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
264 S = C + R
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
265 160 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
266 IF( C.GE.G .OR. MAX( F, C, CA ).GE.SFMAX2 .OR.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
267 $ MIN( R, G, RA ).LE.SFMIN2 )GO TO 170
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
268 F = F*SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
269 C = C*SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
270 CA = CA*SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
271 R = R / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
272 G = G / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
273 RA = RA / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
274 GO TO 160
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
275 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
276 170 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
277 G = C / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
278 180 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
279 IF( G.LT.R .OR. MAX( R, RA ).GE.SFMAX2 .OR.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
280 $ MIN( F, C, G, CA ).LE.SFMIN2 )GO TO 190
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
281 F = F / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
282 C = C / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
283 G = G / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
284 CA = CA / SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
285 R = R*SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
286 RA = RA*SCLFAC
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
287 GO TO 180
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
288 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
289 * Now balance.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
290 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
291 190 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
292 IF( ( C+R ).GE.FACTOR*S )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
293 $ GO TO 200
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
294 IF( F.LT.ONE .AND. SCALE( I ).LT.ONE ) THEN
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
295 IF( F*SCALE( I ).LE.SFMIN1 )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
296 $ GO TO 200
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
297 END IF
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
298 IF( F.GT.ONE .AND. SCALE( I ).GT.ONE ) THEN
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
299 IF( SCALE( I ).GE.SFMAX1 / F )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
300 $ GO TO 200
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
301 END IF
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
302 G = ONE / F
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
303 SCALE( I ) = SCALE( I )*F
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
304 NOCONV = .TRUE.
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
305 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
306 CALL SSCAL( N-K+1, G, A( I, K ), LDA )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
307 CALL SSCAL( L, F, A( 1, I ), 1 )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
308 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
309 200 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
310 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
311 IF( NOCONV )
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
312 $ GO TO 140
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
313 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
314 210 CONTINUE
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
315 ILO = K
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
316 IHI = L
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
317 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
318 RETURN
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
319 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
320 * End of SGEBAL
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
321 *
82be108cc558 First attempt at single precision tyeps
David Bateman <dbateman@free.fr>
parents:
diff changeset
322 END