TESTING/LIN/ztpt01.f(3) Library Functions Manual TESTING/LIN/ztpt01.f(3) NAME TESTING/LIN/ztpt01.f SYNOPSIS Functions/Subroutines subroutine ztpt01 (uplo, diag, n, ap, ainvp, rcond, rwork, resid) ZTPT01 Function/Subroutine Documentation subroutine ztpt01 (character uplo, character diag, integer n, complex*16, dimension( * ) ap, complex*16, dimension( * ) ainvp, double precision rcond, double precision, dimension( * ) rwork, double precision resid) ZTPT01 Purpose: ZTPT01 computes the residual for a triangular matrix A times its inverse when A is stored in packed format: RESID = norm(A*AINV - I) / ( N * norm(A) * norm(AINV) * EPS ), where EPS is the machine epsilon. Parameters UPLO UPLO is CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular DIAG DIAG is CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular N N is INTEGER The order of the matrix A. N >= 0. AP AP is COMPLEX*16 array, dimension (N*(N+1)/2) The original upper or lower triangular matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array AP as follows: if UPLO = 'U', AP((j-1)*j/2 + i) = A(i,j) for 1<=i<=j; if UPLO = 'L', AP((j-1)*(n-j) + j*(j+1)/2 + i-j) = A(i,j) for j<=i<=n. AINVP AINVP is COMPLEX*16 array, dimension (N*(N+1)/2) On entry, the (triangular) inverse of the matrix A, packed columnwise in a linear array as in AP. On exit, the contents of AINVP are destroyed. RCOND RCOND is DOUBLE PRECISION The reciprocal condition number of A, computed as 1/(norm(A) * norm(AINV)). RWORK RWORK is DOUBLE PRECISION array, dimension (N) RESID RESID is DOUBLE PRECISION norm(A*AINV - I) / ( N * norm(A) * norm(AINV) * EPS ) Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line 108 of file ztpt01.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/LIN/ztpt01.f(3)