 LAPACK  3.10.0 LAPACK: Linear Algebra PACKage

## ◆ cla_gerpvgrw()

 real function cla_gerpvgrw ( integer N, integer NCOLS, complex, dimension( lda, * ) A, integer LDA, complex, dimension( ldaf, * ) AF, integer LDAF )

CLA_GERPVGRW multiplies a square real matrix by a complex matrix.

Purpose:
``` CLA_GERPVGRW computes the reciprocal pivot growth factor
norm(A)/norm(U). The "max absolute element" norm is used. If this is
much less than 1, the stability of the LU factorization of the
(equilibrated) matrix A could be poor. This also means that the
solution X, estimated condition numbers, and error bounds could be
unreliable.```
Parameters
 [in] N ``` N is INTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0.``` [in] NCOLS ``` NCOLS is INTEGER The number of columns of the matrix A. NCOLS >= 0.``` [in] A ``` A is COMPLEX array, dimension (LDA,N) On entry, the N-by-N matrix A.``` [in] LDA ``` LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N).``` [in] AF ``` AF is COMPLEX array, dimension (LDAF,N) The factors L and U from the factorization A = P*L*U as computed by CGETRF.``` [in] LDAF ``` LDAF is INTEGER The leading dimension of the array AF. LDAF >= max(1,N).```

Definition at line 97 of file cla_gerpvgrw.f.

98 *
99 * -- LAPACK computational routine --
100 * -- LAPACK is a software package provided by Univ. of Tennessee, --
101 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
102 *
103 * .. Scalar Arguments ..
104  INTEGER N, NCOLS, LDA, LDAF
105 * ..
106 * .. Array Arguments ..
107  COMPLEX A( LDA, * ), AF( LDAF, * )
108 * ..
109 *
110 * =====================================================================
111 *
112 * .. Local Scalars ..
113  INTEGER I, J
114  REAL AMAX, UMAX, RPVGRW
115  COMPLEX ZDUM
116 * ..
117 * .. Intrinsic Functions ..
118  INTRINSIC max, min, abs, real, aimag
119 * ..
120 * .. Statement Functions ..
121  REAL CABS1
122 * ..
123 * .. Statement Function Definitions ..
124  cabs1( zdum ) = abs( real( zdum ) ) + abs( aimag( zdum ) )
125 * ..
126 * .. Executable Statements ..
127 *
128  rpvgrw = 1.0
129
130  DO j = 1, ncols
131  amax = 0.0
132  umax = 0.0
133  DO i = 1, n
134  amax = max( cabs1( a( i, j ) ), amax )
135  END DO
136  DO i = 1, j
137  umax = max( cabs1( af( i, j ) ), umax )
138  END DO
139  IF ( umax /= 0.0 ) THEN
140  rpvgrw = min( amax / umax, rpvgrw )
141  END IF
142  END DO
143  cla_gerpvgrw = rpvgrw
144 *
145 * End of CLA_GERPVGRW
146 *
real function cla_gerpvgrw(N, NCOLS, A, LDA, AF, LDAF)
CLA_GERPVGRW multiplies a square real matrix by a complex matrix.
Definition: cla_gerpvgrw.f:98
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