![]() |
LAPACK
3.5.0
LAPACK: Linear Algebra PACKage
|
Go to the source code of this file.
Functions/Subroutines | |
subroutine | dlarrc (JOBT, N, VL, VU, D, E, PIVMIN, EIGCNT, LCNT, RCNT, INFO) |
DLARRC computes the number of eigenvalues of the symmetric tridiagonal matrix. |
subroutine dlarrc | ( | character | JOBT, |
integer | N, | ||
double precision | VL, | ||
double precision | VU, | ||
double precision, dimension( * ) | D, | ||
double precision, dimension( * ) | E, | ||
double precision | PIVMIN, | ||
integer | EIGCNT, | ||
integer | LCNT, | ||
integer | RCNT, | ||
integer | INFO | ||
) |
DLARRC computes the number of eigenvalues of the symmetric tridiagonal matrix.
Download DLARRC + dependencies [TGZ] [ZIP] [TXT]Find the number of eigenvalues of the symmetric tridiagonal matrix T that are in the interval (VL,VU] if JOBT = 'T', and of L D L^T if JOBT = 'L'.
[in] | JOBT | JOBT is CHARACTER*1 = 'T': Compute Sturm count for matrix T. = 'L': Compute Sturm count for matrix L D L^T. |
[in] | N | N is INTEGER The order of the matrix. N > 0. |
[in] | VL | VL is DOUBLE PRECISION |
[in] | VU | VU is DOUBLE PRECISION The lower and upper bounds for the eigenvalues. |
[in] | D | D is DOUBLE PRECISION array, dimension (N) JOBT = 'T': The N diagonal elements of the tridiagonal matrix T. JOBT = 'L': The N diagonal elements of the diagonal matrix D. |
[in] | E | E is DOUBLE PRECISION array, dimension (N) JOBT = 'T': The N-1 offdiagonal elements of the matrix T. JOBT = 'L': The N-1 offdiagonal elements of the matrix L. |
[in] | PIVMIN | PIVMIN is DOUBLE PRECISION The minimum pivot in the Sturm sequence for T. |
[out] | EIGCNT | EIGCNT is INTEGER The number of eigenvalues of the symmetric tridiagonal matrix T that are in the interval (VL,VU] |
[out] | LCNT | LCNT is INTEGER |
[out] | RCNT | RCNT is INTEGER The left and right negcounts of the interval. |
[out] | INFO | INFO is INTEGER |
Definition at line 136 of file dlarrc.f.