.TH "chpev.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME chpev.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBchpev\fP (JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, RWORK, INFO)" .br .RI "\fI\fB CHPEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices\fP \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine chpev (characterJOBZ, characterUPLO, integerN, complex, dimension( * )AP, real, dimension( * )W, complex, dimension( ldz, * )Z, integerLDZ, complex, dimension( * )WORK, real, dimension( * )RWORK, integerINFO)" .PP \fB CHPEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices\fP .PP \fBPurpose: \fP .RS 4 .PP .nf CHPEV computes all the eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix in packed storage. .fi .PP .RE .PP \fBParameters:\fP .RS 4 \fIJOBZ\fP .PP .nf JOBZ is CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. .fi .PP .br \fIUPLO\fP .PP .nf UPLO is CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. .fi .PP .br \fIN\fP .PP .nf N is INTEGER The order of the matrix A. N >= 0. .fi .PP .br \fIAP\fP .PP .nf AP is COMPLEX array, dimension (N*(N+1)/2) On entry, the upper or lower triangle of the Hermitian 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(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n. On exit, AP is overwritten by values generated during the reduction to tridiagonal form. If UPLO = 'U', the diagonal and first superdiagonal of the tridiagonal matrix T overwrite the corresponding elements of A, and if UPLO = 'L', the diagonal and first subdiagonal of T overwrite the corresponding elements of A. .fi .PP .br \fIW\fP .PP .nf W is REAL array, dimension (N) If INFO = 0, the eigenvalues in ascending order. .fi .PP .br \fIZ\fP .PP .nf Z is COMPLEX array, dimension (LDZ, N) If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal eigenvectors of the matrix A, with the i-th column of Z holding the eigenvector associated with W(i). If JOBZ = 'N', then Z is not referenced. .fi .PP .br \fILDZ\fP .PP .nf LDZ is INTEGER The leading dimension of the array Z. LDZ >= 1, and if JOBZ = 'V', LDZ >= max(1,N). .fi .PP .br \fIWORK\fP .PP .nf WORK is COMPLEX array, dimension (max(1, 2*N-1)) .fi .PP .br \fIRWORK\fP .PP .nf RWORK is REAL array, dimension (max(1, 3*N-2)) .fi .PP .br \fIINFO\fP .PP .nf INFO is INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. > 0: if INFO = i, the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero. .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 \fBDate:\fP .RS 4 November 2011 .RE .PP .PP Definition at line 138 of file chpev\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.