.TH "TESTING/LIN/cgtt01.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME TESTING/LIN/cgtt01.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBcgtt01\fP (n, dl, d, du, dlf, df, duf, du2, ipiv, work, ldwork, rwork, resid)" .br .RI "\fBCGTT01\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine cgtt01 (integer n, complex, dimension( * ) dl, complex, dimension( * ) d, complex, dimension( * ) du, complex, dimension( * ) dlf, complex, dimension( * ) df, complex, dimension( * ) duf, complex, dimension( * ) du2, integer, dimension( * ) ipiv, complex, dimension( ldwork, * ) work, integer ldwork, real, dimension( * ) rwork, real resid)" .PP \fBCGTT01\fP .PP \fBPurpose:\fP .RS 4 .PP .nf CGTT01 reconstructs a tridiagonal matrix A from its LU factorization and computes the residual norm(L*U - A) / ( norm(A) * EPS ), where EPS is the machine epsilon\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIN\fP .PP .nf N is INTEGER The order of the matrix A\&. N >= 0\&. .fi .PP .br \fIDL\fP .PP .nf DL is COMPLEX array, dimension (N-1) The (n-1) sub-diagonal elements of A\&. .fi .PP .br \fID\fP .PP .nf D is COMPLEX array, dimension (N) The diagonal elements of A\&. .fi .PP .br \fIDU\fP .PP .nf DU is COMPLEX array, dimension (N-1) The (n-1) super-diagonal elements of A\&. .fi .PP .br \fIDLF\fP .PP .nf DLF is COMPLEX array, dimension (N-1) The (n-1) multipliers that define the matrix L from the LU factorization of A\&. .fi .PP .br \fIDF\fP .PP .nf DF is COMPLEX array, dimension (N) The n diagonal elements of the upper triangular matrix U from the LU factorization of A\&. .fi .PP .br \fIDUF\fP .PP .nf DUF is COMPLEX array, dimension (N-1) The (n-1) elements of the first super-diagonal of U\&. .fi .PP .br \fIDU2\fP .PP .nf DU2 is COMPLEX array, dimension (N-2) The (n-2) elements of the second super-diagonal of U\&. .fi .PP .br \fIIPIV\fP .PP .nf IPIV is INTEGER array, dimension (N) The pivot indices; for 1 <= i <= n, row i of the matrix was interchanged with row IPIV(i)\&. IPIV(i) will always be either i or i+1; IPIV(i) = i indicates a row interchange was not required\&. .fi .PP .br \fIWORK\fP .PP .nf WORK is COMPLEX array, dimension (LDWORK,N) .fi .PP .br \fILDWORK\fP .PP .nf LDWORK is INTEGER The leading dimension of the array WORK\&. LDWORK >= max(1,N)\&. .fi .PP .br \fIRWORK\fP .PP .nf RWORK is REAL array, dimension (N) .fi .PP .br \fIRESID\fP .PP .nf RESID is REAL The scaled residual: norm(L*U - A) / (norm(A) * EPS) .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 \fB132\fP of file \fBcgtt01\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.