LAPACK
3.6.1
LAPACK: Linear Algebra PACKage
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subroutine zhbev | ( | character | JOBZ, |
character | UPLO, | ||
integer | N, | ||
integer | KD, | ||
complex*16, dimension( ldab, * ) | AB, | ||
integer | LDAB, | ||
double precision, dimension( * ) | W, | ||
complex*16, dimension( ldz, * ) | Z, | ||
integer | LDZ, | ||
complex*16, dimension( * ) | WORK, | ||
double precision, dimension( * ) | RWORK, | ||
integer | INFO | ||
) |
ZHBEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices
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ZHBEV computes all the eigenvalues and, optionally, eigenvectors of a complex Hermitian band matrix A.
[in] | JOBZ | JOBZ is CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. |
[in] | UPLO | UPLO is CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. |
[in] | N | N is INTEGER The order of the matrix A. N >= 0. |
[in] | KD | KD is INTEGER The number of superdiagonals of the matrix A if UPLO = 'U', or the number of subdiagonals if UPLO = 'L'. KD >= 0. |
[in,out] | AB | AB is COMPLEX*16 array, dimension (LDAB, N) On entry, the upper or lower triangle of the Hermitian 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). On exit, AB is overwritten by values generated during the reduction to tridiagonal form. If UPLO = 'U', the first superdiagonal and the diagonal of the tridiagonal matrix T are returned in rows KD and KD+1 of AB, and if UPLO = 'L', the diagonal and first subdiagonal of T are returned in the first two rows of AB. |
[in] | LDAB | LDAB is INTEGER The leading dimension of the array AB. LDAB >= KD + 1. |
[out] | W | W is DOUBLE PRECISION array, dimension (N) If INFO = 0, the eigenvalues in ascending order. |
[out] | Z | Z is COMPLEX*16 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. |
[in] | LDZ | LDZ is INTEGER The leading dimension of the array Z. LDZ >= 1, and if JOBZ = 'V', LDZ >= max(1,N). |
[out] | WORK | WORK is COMPLEX*16 array, dimension (N) |
[out] | RWORK | RWORK is DOUBLE PRECISION array, dimension (max(1,3*N-2)) |
[out] | INFO | 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. |
Definition at line 154 of file zhbev.f.