All Packages Class Hierarchy This Package Previous Next Index
java.lang.Object | +----org.netlib.lapack.Dsyevd
Following is the description from the original Fortran source. For each array argument, the Java version will include an integer offset parameter, so the arguments may not match the description exactly. Contact seymour@cs.utk.edu with any questions.* .. * * Purpose * ======= * * DSYEVD computes all eigenvalues and, optionally, eigenvectors of a * real symmetric matrix A. If eigenvectors are desired, it uses a * divide and conquer algorithm. * * The divide and conquer algorithm makes very mild assumptions about * floating point arithmetic. It will work on machines with a guard * digit in add/subtract, or on those binary machines without guard * digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or * Cray-2. It could conceivably fail on hexadecimal or decimal machines * without guard digits, but we know of none. * * Arguments * ========= * * JOBZ (input) CHARACTER*1 * = 'N': Compute eigenvalues only; * = 'V': Compute eigenvalues and eigenvectors. * * UPLO (input) CHARACTER*1 * = 'U': Upper triangle of A is stored; * = 'L': Lower triangle of A is stored. * * N (input) INTEGER * The order of the matrix A. N >= 0. * * A (input/output) DOUBLE PRECISION array, dimension (LDA, N) * On entry, the symmetric matrix A. If UPLO = 'U', the * leading N-by-N upper triangular part of A contains the * upper triangular part of the matrix A. If UPLO = 'L', * the leading N-by-N lower triangular part of A contains * the lower triangular part of the matrix A. * On exit, if JOBZ = 'V', then if INFO = 0, A contains the * orthonormal eigenvectors of the matrix A. * If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') * or the upper triangle (if UPLO='U') of A, including the * diagonal, is destroyed. * * LDA (input) INTEGER * The leading dimension of the array A. LDA >= max(1,N). * * W (output) DOUBLE PRECISION array, dimension (N) * If INFO = 0, the eigenvalues in ascending order. * * WORK (workspace/output) DOUBLE PRECISION array, * dimension (LWORK) * On exit, if LWORK > 0, WORK(1) returns the optimal LWORK. * * LWORK (input) INTEGER * The dimension of the array WORK. * If N <= 1, LWORK must be at least 1. * If JOBZ = 'N' and N > 1, LWORK must be at least 2*N+1. * If JOBZ = 'V' and N > 1, LWORK must be at least * 1 + 5*N + 2*N*lg N + 3*N**2, * where lg( N ) = smallest integer k such * that 2**k >= N. * * IWORK (workspace/output) INTEGER array, dimension (LIWORK) * On exit, if LIWORK > 0, IWORK(1) returns the optimal LIWORK. * * LIWORK (input) INTEGER * The dimension of the array IWORK. * If N <= 1, LIWORK must be at least 1. * If JOBZ = 'N' and N > 1, LIWORK must be at least 1. * If JOBZ = 'V' and N > 1, LIWORK must be at least 2 + 5*N. * * INFO (output) 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. * * ===================================================================== * * .. Parameters ..
Dsyevd()
dsyevd(String, String, int, double[], int, int, double[], int, double[], int, int, int[], int, int, intW)
Dsyevd
public Dsyevd()
dsyevd
public static void dsyevd(String jobz,
String uplo,
int n,
double a[],
int _a_offset,
int lda,
double w[],
int _w_offset,
double work[],
int _work_offset,
int lwork,
int iwork[],
int _iwork_offset,
int liwork,
intW info)
All Packages Class Hierarchy This Package Previous Next Index