.TH "TESTING/EIG/zunt01.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME TESTING/EIG/zunt01.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBzunt01\fP (rowcol, m, n, u, ldu, work, lwork, rwork, resid)" .br .RI "\fBZUNT01\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine zunt01 (character rowcol, integer m, integer n, complex*16, dimension( ldu, * ) u, integer ldu, complex*16, dimension( * ) work, integer lwork, double precision, dimension( * ) rwork, double precision resid)" .PP \fBZUNT01\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZUNT01 checks that the matrix U is unitary by computing the ratio !> !> RESID = norm( I - U*U' ) / ( n * EPS ), if ROWCOL = 'R', !> or !> RESID = norm( I - U'*U ) / ( m * EPS ), if ROWCOL = 'C'\&. !> !> Alternatively, if there isn't sufficient workspace to form !> I - U*U' or I - U'*U, the ratio is computed as !> !> RESID = abs( I - U*U' ) / ( n * EPS ), if ROWCOL = 'R', !> or !> RESID = abs( I - U'*U ) / ( m * EPS ), if ROWCOL = 'C'\&. !> !> where EPS is the machine precision\&. ROWCOL is used only if m = n; !> if m > n, ROWCOL is assumed to be 'C', and if m < n, ROWCOL is !> assumed to be 'R'\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIROWCOL\fP .PP .nf !> ROWCOL is CHARACTER !> Specifies whether the rows or columns of U should be checked !> for orthogonality\&. Used only if M = N\&. !> = 'R': Check for orthogonal rows of U !> = 'C': Check for orthogonal columns of U !> .fi .PP .br \fIM\fP .PP .nf !> M is INTEGER !> The number of rows of the matrix U\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The number of columns of the matrix U\&. !> .fi .PP .br \fIU\fP .PP .nf !> U is COMPLEX*16 array, dimension (LDU,N) !> The unitary matrix U\&. U is checked for orthogonal columns !> if m > n or if m = n and ROWCOL = 'C'\&. U is checked for !> orthogonal rows if m < n or if m = n and ROWCOL = 'R'\&. !> .fi .PP .br \fILDU\fP .PP .nf !> LDU is INTEGER !> The leading dimension of the array U\&. LDU >= max(1,M)\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is COMPLEX*16 array, dimension (LWORK) !> .fi .PP .br \fILWORK\fP .PP .nf !> LWORK is INTEGER !> The length of the array WORK\&. For best performance, LWORK !> should be at least N*N if ROWCOL = 'C' or M*M if !> ROWCOL = 'R', but the test will be done even if LWORK is 0\&. !> .fi .PP .br \fIRWORK\fP .PP .nf !> RWORK is DOUBLE PRECISION array, dimension (min(M,N)) !> Used only if LWORK is large enough to use the Level 3 BLAS !> code\&. !> .fi .PP .br \fIRESID\fP .PP .nf !> RESID is DOUBLE PRECISION !> RESID = norm( I - U * U' ) / ( n * EPS ), if ROWCOL = 'R', or !> RESID = norm( I - U' * U ) / ( m * EPS ), if ROWCOL = 'C'\&. !> .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 \fB124\fP of file \fBzunt01\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.