.TH "TESTING/LIN/ctbt06.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME TESTING/LIN/ctbt06.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBctbt06\fP (rcond, rcondc, uplo, diag, n, kd, ab, ldab, rwork, rat)" .br .RI "\fBCTBT06\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine ctbt06 (real rcond, real rcondc, character uplo, character diag, integer n, integer kd, complex, dimension( ldab, * ) ab, integer ldab, real, dimension( * ) rwork, real rat)" .PP \fBCTBT06\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> CTBT06 computes a test ratio comparing RCOND (the reciprocal !> condition number of a triangular matrix A) and RCONDC, the estimate !> computed by CTBCON\&. Information about the triangular matrix A is !> used if one estimate is zero and the other is non-zero to decide if !> underflow in the estimate is justified\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIRCOND\fP .PP .nf !> RCOND is REAL !> The estimate of the reciprocal condition number obtained by !> forming the explicit inverse of the matrix A and computing !> RCOND = 1/( norm(A) * norm(inv(A)) )\&. !> .fi .PP .br \fIRCONDC\fP .PP .nf !> RCONDC is REAL !> The estimate of the reciprocal condition number computed by !> CTBCON\&. !> .fi .PP .br \fIUPLO\fP .PP .nf !> UPLO is CHARACTER !> Specifies whether the matrix A is upper or lower triangular\&. !> = 'U': Upper triangular !> = 'L': Lower triangular !> .fi .PP .br \fIDIAG\fP .PP .nf !> DIAG is CHARACTER !> Specifies whether or not the matrix A is unit triangular\&. !> = 'N': Non-unit triangular !> = 'U': Unit triangular !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The order of the matrix A\&. N >= 0\&. !> .fi .PP .br \fIKD\fP .PP .nf !> KD is INTEGER !> The number of superdiagonals or subdiagonals of the !> triangular band matrix A\&. KD >= 0\&. !> .fi .PP .br \fIAB\fP .PP .nf !> AB is COMPLEX array, dimension (LDAB,N) !> The upper or lower triangular band matrix A, stored in the !> first kd+1 rows of the array\&. The j-th column of A is stored !> in the j-th column of the array AB as follows: !> if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; !> if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd)\&. !> .fi .PP .br \fILDAB\fP .PP .nf !> LDAB is INTEGER !> The leading dimension of the array AB\&. LDAB >= KD+1\&. !> .fi .PP .br \fIRWORK\fP .PP .nf !> RWORK is REAL array, dimension (N) !> .fi .PP .br \fIRAT\fP .PP .nf !> RAT is REAL !> The test ratio\&. If both RCOND and RCONDC are nonzero, !> RAT = MAX( RCOND, RCONDC )/MIN( RCOND, RCONDC ) - 1\&. !> If RAT = 0, the two estimates are exactly the same\&. !> .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 \fBctbt06\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.