.TH "TESTING/LIN/dqrt17.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
TESTING/LIN/dqrt17.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "double precision function \fBdqrt17\fP (trans, iresid, m, n, nrhs, a, lda, x, ldx, b, ldb, c, work, lwork)"
.br
.RI "\fBDQRT17\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "double precision function dqrt17 (character trans, integer iresid, integer m, integer n, integer nrhs, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldx, * ) x, integer ldx, double precision, dimension( ldb, * ) b, integer ldb, double precision, dimension( ldb, * ) c, double precision, dimension( lwork ) work, integer lwork)"

.PP
\fBDQRT17\fP 
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 DQRT17 computes the ratio

    norm(R**T * op(A)) / ( norm(A) * alpha * max(M,N,NRHS) * EPS ),

 where R = B - op(A)*X, op(A) is A or A**T, depending on TRANS, EPS
 is the machine epsilon, and

    alpha = norm(B) if IRESID = 1 (zero-residual problem)
    alpha = norm(R) if IRESID = 2 (otherwise)\&.

 The norm used is the 1-norm\&.
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fITRANS\fP 
.PP
.nf
          TRANS is CHARACTER*1
          Specifies whether or not the transpose of A is used\&.
          = 'N':  No transpose, op(A) = A\&.
          = 'T':  Transpose, op(A) = A**T\&.
.fi
.PP
.br
\fIIRESID\fP 
.PP
.nf
          IRESID is INTEGER
          IRESID = 1 indicates zero-residual problem\&.
          IRESID = 2 indicates non-zero residual\&.
.fi
.PP
.br
\fIM\fP 
.PP
.nf
          M is INTEGER
          The number of rows of the matrix A\&.
          If TRANS = 'N', the number of rows of the matrix B\&.
          If TRANS = 'T', the number of rows of the matrix X\&.
.fi
.PP
.br
\fIN\fP 
.PP
.nf
          N is INTEGER
          The number of columns of the matrix  A\&.
          If TRANS = 'N', the number of rows of the matrix X\&.
          If TRANS = 'T', the number of rows of the matrix B\&.
.fi
.PP
.br
\fINRHS\fP 
.PP
.nf
          NRHS is INTEGER
          The number of columns of the matrices X and B\&.
.fi
.PP
.br
\fIA\fP 
.PP
.nf
          A is DOUBLE PRECISION array, dimension (LDA,N)
          The m-by-n matrix A\&.
.fi
.PP
.br
\fILDA\fP 
.PP
.nf
          LDA is INTEGER
          The leading dimension of the array A\&. LDA >= M\&.
.fi
.PP
.br
\fIX\fP 
.PP
.nf
          X is DOUBLE PRECISION array, dimension (LDX,NRHS)
          If TRANS = 'N', the n-by-nrhs matrix X\&.
          If TRANS = 'T', the m-by-nrhs matrix X\&.
.fi
.PP
.br
\fILDX\fP 
.PP
.nf
          LDX is INTEGER
          The leading dimension of the array X\&.
          If TRANS = 'N', LDX >= N\&.
          If TRANS = 'T', LDX >= M\&.
.fi
.PP
.br
\fIB\fP 
.PP
.nf
          B is DOUBLE PRECISION array, dimension (LDB,NRHS)
          If TRANS = 'N', the m-by-nrhs matrix B\&.
          If TRANS = 'T', the n-by-nrhs matrix B\&.
.fi
.PP
.br
\fILDB\fP 
.PP
.nf
          LDB is INTEGER
          The leading dimension of the array B\&.
          If TRANS = 'N', LDB >= M\&.
          If TRANS = 'T', LDB >= N\&.
.fi
.PP
.br
\fIC\fP 
.PP
.nf
          C is DOUBLE PRECISION array, dimension (LDB,NRHS)
.fi
.PP
.br
\fIWORK\fP 
.PP
.nf
          WORK is DOUBLE PRECISION array, dimension (LWORK)
.fi
.PP
.br
\fILWORK\fP 
.PP
.nf
          LWORK is INTEGER
          The length of the array WORK\&.  LWORK >= NRHS*(M+N)\&.
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 
.PP
Univ\&. of California Berkeley 
.PP
Univ\&. of Colorado Denver 
.PP
NAG Ltd\&. 
.RE
.PP

.PP
Definition at line \fB151\fP of file \fBdqrt17\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.