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java.lang.Object | +----org.netlib.lapack.Dlaed0
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 * ======= * * DLAED0 computes all eigenvalues and corresponding eigenvectors of a * symmetric tridiagonal matrix using the divide and conquer method. * * Arguments * ========= * * ICOMPQ (input) INTEGER * = 0: Compute eigenvalues only. * = 1: Compute eigenvectors of original dense symmetric matrix * also. On entry, Q contains the orthogonal matrix used * to reduce the original matrix to tridiagonal form. * = 2: Compute eigenvalues and eigenvectors of tridiagonal * matrix. * * QSIZ (input) INTEGER * The dimension of the orthogonal matrix used to reduce * the full matrix to tridiagonal form. QSIZ >= N if ICOMPQ = 1. * * N (input) INTEGER * The dimension of the symmetric tridiagonal matrix. N >= 0. * * D (input/output) DOUBLE PRECISION array, dimension (N) * On entry, the main diagonal of the tridiagonal matrix. * On exit, its eigenvalues. * * E (input) DOUBLE PRECISION array, dimension (N-1) * The off-diagonal elements of the tridiagonal matrix. * On exit, E has been destroyed. * * Q (input/output) DOUBLE PRECISION array, dimension (LDQ, N) * On entry, Q must contain an N-by-N orthogonal matrix. * If ICOMPQ = 0 Q is not referenced. * If ICOMPQ = 1 On entry, Q is a subset of the columns of the * orthogonal matrix used to reduce the full * matrix to tridiagonal form corresponding to * the subset of the full matrix which is being * decomposed at this time. * If ICOMPQ = 2 On entry, Q will be the identity matrix. * On exit, Q contains the eigenvectors of the * tridiagonal matrix. * * LDQ (input) INTEGER * The leading dimension of the array Q. If eigenvectors are * desired, then LDQ >= max(1,N). In any case, LDQ >= 1. * * QSTORE (workspace) DOUBLE PRECISION array, dimension (LDQS, N) * Referenced only when ICOMPQ = 1. Used to store parts of * the eigenvector matrix when the updating matrix multiplies * take place. * * LDQS (input) INTEGER * The leading dimension of the array QSTORE. If ICOMPQ = 1, * then LDQS >= max(1,N). In any case, LDQS >= 1. * * WORK (workspace) DOUBLE PRECISION array, * dimension (1 + 3*N + 2*N*lg N + 2*N**2) * ( lg( N ) = smallest integer k * such that 2^k >= N ) * * IWORK (workspace) INTEGER array, * If ICOMPQ = 0 or 1, the dimension of IWORK must be at least * 6 + 6*N + 5*N*lg N. * ( lg( N ) = smallest integer k * such that 2^k >= N ) * If ICOMPQ = 2, the dimension of IWORK 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: The algorithm failed to compute an eigenvalue while * working on the submatrix lying in rows and columns * INFO/(N+1) through mod(INFO,N+1). * * ===================================================================== * * .. Parameters ..
Dlaed0()
dlaed0(int, int, int, double[], int, double[], int, double[], int, int, double[], int, int, double[], int, int[], int, intW)
Dlaed0
public Dlaed0()
dlaed0
public static void dlaed0(int icompq,
int qsiz,
int n,
double d[],
int _d_offset,
double e[],
int _e_offset,
double q[],
int _q_offset,
int ldq,
double qstore[],
int _qstore_offset,
int ldqs,
double work[],
int _work_offset,
int iwork[],
int _iwork_offset,
intW info)
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