Overview | Package | Class | Tree | Deprecated | Index | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

## org.netlib.lapack
Class Dspevd

    java.lang.Object
      org.netlib.lapack.Dspevd

    public class Dspevd

extends java.lang.Object

    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
     *  =======
     *
     *  DSPEVD computes all the eigenvalues and, optionally, eigenvectors
     *  of a real symmetric matrix A in packed storage. 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.
     *
     *  AP      (input/output) DOUBLE PRECISION array, dimension (N*(N+1)/2)

     *          On entry, the upper or lower triangle of the symmetric 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.
     *
     *  W       (output) DOUBLE PRECISION array, dimension (N)
     *          If INFO = 0, the eigenvalues in ascending order.
     *
     *  Z       (output) DOUBLE PRECISION 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.
     *
     *  LDZ     (input) INTEGER
     *          The leading dimension of the array Z.  LDZ >= 1, and if
     *          JOBZ = 'V', LDZ >= max(1,N).
     *
     *  WORK    (workspace/output) DOUBLE PRECISION array,
     *                                         dimension (LWORK)
     *          On exit, if INFO = 0, WORK(1) returns the required 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.
     *          If JOBZ = 'V' and N > 1, LWORK must be at least
     *                                                 1 + 6*N + N**2.
     *
     *          If LWORK = -1, then a workspace query is assumed; the routine
     *          only calculates the required sizes of the WORK and IWORK
     *          arrays, returns these values as the first entries of the WORK
     *          and IWORK arrays, and no error message related to LWORK or
     *          LIWORK is issued by XERBLA.
     *
     *  IWORK   (workspace/output) INTEGER array, dimension (MAX(1,LIWORK))
     *          On exit, if INFO = 0, IWORK(1) returns the required LIWORK.
     *
     *  LIWORK  (input) INTEGER
     *          The dimension of the array IWORK.
     *          If JOBZ  = 'N' or N <= 1, LIWORK must be at least 1.
     *          If JOBZ  = 'V' and N > 1, LIWORK must be at least 3 + 5*N.
     *
     *          If LIWORK = -1, then a workspace query is assumed; the
     *          routine only calculates the required sizes of the WORK and
     *          IWORK arrays, returns these values as the first entries of
     *          the WORK and IWORK arrays, and no error message related to
     *          LWORK or LIWORK is issued by XERBLA.
     *
     *  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 ..

Constructor Summary
`Dspevd()`

Method Summary
`static void` | `dspevd(java.lang.String jobz, java.lang.String uplo, int n, double[] ap, int _ap_offset, double[] w, int _w_offset, double[] z, int _z_offset, int ldz, double[] work, int _work_offset, int lwork, int[] iwork, int _iwork_offset, int liwork, intW info)`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### Dspevd

    public Dspevd()

Method Detail

### dspevd

    public static void dspevd(java.lang.String jobz,
                              java.lang.String uplo,
                              int n,
                              double[] ap,
                              int _ap_offset,
                              double[] w,
                              int _w_offset,
                              double[] z,
                              int _z_offset,
                              int ldz,
                              double[] work,
                              int _work_offset,
                              int lwork,
                              int[] iwork,
                              int _iwork_offset,
                              int liwork,
                              intW info)

Overview | Package | Class | Tree | Deprecated | Index | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD