org.netlib.lapack
Class Dgeev

java.lang.Object
  org.netlib.lapack.Dgeev

public class Dgeev
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
 *  =======
 *
 *  DGEEV computes for an N-by-N real nonsymmetric matrix A, the
 *  eigenvalues and, optionally, the left and/or right eigenvectors.
 *
 *  The right eigenvector v(j) of A satisfies
 *                   A * v(j) = lambda(j) * v(j)
 *  where lambda(j) is its eigenvalue.
 *  The left eigenvector u(j) of A satisfies
 *                u(j)**H * A = lambda(j) * u(j)**H
 *  where u(j)**H denotes the conjugate transpose of u(j).
 *
 *  The computed eigenvectors are normalized to have Euclidean norm
 *  equal to 1 and largest component real.
 *
 *  Arguments
 *  =========
 *
 *  JOBVL   (input) CHARACTER*1
 *          = 'N': left eigenvectors of A are not computed;
 *          = 'V': left eigenvectors of A are computed.
 *
 *  JOBVR   (input) CHARACTER*1
 *          = 'N': right eigenvectors of A are not computed;
 *          = 'V': right eigenvectors of A are computed.
 *
 *  N       (input) INTEGER
 *          The order of the matrix A. N >= 0.
 *
 *  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
 *          On entry, the N-by-N matrix A.
 *          On exit, A has been overwritten.
 *
 *  LDA     (input) INTEGER
 *          The leading dimension of the array A.  LDA >= max(1,N).
 *
 *  WR      (output) DOUBLE PRECISION array, dimension (N)
 *  WI      (output) DOUBLE PRECISION array, dimension (N)
 *          WR and WI contain the real and imaginary parts,
 *          respectively, of the computed eigenvalues.  Complex
 *          conjugate pairs of eigenvalues appear consecutively
 *          with the eigenvalue having the positive imaginary part
 *          first.
 *
 *  VL      (output) DOUBLE PRECISION array, dimension (LDVL,N)
 *          If JOBVL = 'V', the left eigenvectors u(j) are stored one
 *          after another in the columns of VL, in the same order
 *          as their eigenvalues.
 *          If JOBVL = 'N', VL is not referenced.
 *          If the j-th eigenvalue is real, then u(j) = VL(:,j),
 *          the j-th column of VL.
 *          If the j-th and (j+1)-st eigenvalues form a complex
 *          conjugate pair, then u(j) = VL(:,j) + i*VL(:,j+1) and
 *          u(j+1) = VL(:,j) - i*VL(:,j+1).
 *
 *  LDVL    (input) INTEGER
 *          The leading dimension of the array VL.  LDVL >= 1; if
 *          JOBVL = 'V', LDVL >= N.
 *
 *  VR      (output) DOUBLE PRECISION array, dimension (LDVR,N)
 *          If JOBVR = 'V', the right eigenvectors v(j) are stored one
 *          after another in the columns of VR, in the same order
 *          as their eigenvalues.
 *          If JOBVR = 'N', VR is not referenced.
 *          If the j-th eigenvalue is real, then v(j) = VR(:,j),
 *          the j-th column of VR.
 *          If the j-th and (j+1)-st eigenvalues form a complex
 *          conjugate pair, then v(j) = VR(:,j) + i*VR(:,j+1) and
 *          v(j+1) = VR(:,j) - i*VR(:,j+1).
 *
 *  LDVR    (input) INTEGER
 *          The leading dimension of the array VR.  LDVR >= 1; if
 *          JOBVR = 'V', LDVR >= N.
 *
 *  WORK    (workspace/output) DOUBLE PRECISION array, dimension (LWORK)

 *          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
 *
 *  LWORK   (input) INTEGER
 *          The dimension of the array WORK.  LWORK >= max(1,3*N), and
 *          if JOBVL = 'V' or JOBVR = 'V', LWORK >= 4*N.  For good
 *          performance, LWORK must generally be larger.
 *
 *          If LWORK = -1, then a workspace query is assumed; the routine
 *          only calculates the optimal size of the WORK array, returns
 *          this value as the first entry of the WORK array, and no error
 *          message related to LWORK 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 QR algorithm failed to compute all the
 *                eigenvalues, and no eigenvectors have been computed;
 *                elements i+1:N of WR and WI contain eigenvalues which
 *                have converged.
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

Dgeev()

Method Summary

static void

dgeev(java.lang.String jobvl, java.lang.String jobvr, int n, double[] a, int _a_offset, int lda, double[] wr, int _wr_offset, double[] wi, int _wi_offset, double[] vl, int _vl_offset, int ldvl, double[] vr, int _vr_offset, int ldvr, double[] work, int _work_offset, int lwork, intW info)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Dgeev

public Dgeev()

Method Detail

dgeev

public static void dgeev(java.lang.String jobvl,
                         java.lang.String jobvr,
                         int n,
                         double[] a,
                         int _a_offset,
                         int lda,
                         double[] wr,
                         int _wr_offset,
                         double[] wi,
                         int _wi_offset,
                         double[] vl,
                         int _vl_offset,
                         int ldvl,
                         double[] vr,
                         int _vr_offset,
                         int ldvr,
                         double[] work,
                         int _work_offset,
                         int lwork,
                         intW info)