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Class org.netlib.lapack.Dsbtrd

java.lang.Object
   |
   +----org.netlib.lapack.Dsbtrd

public class Dsbtrd

extends 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
 *  =======
 *
 *  DSBTRD reduces a real symmetric band matrix A to symmetric
 *  tridiagonal form T by an orthogonal similarity transformation:
 *  Q**T * A * Q = T.
 *
 *  Arguments
 *  =========
 *
 *  VECT    (input) CHARACTER*1
 *          = 'N':  do not form Q;
 *          = 'V':  form Q;
 *          = 'U':  update a matrix X, by forming X*Q.
 *
 *  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.
 *
 *  KD      (input) INTEGER
 *          The number of superdiagonals of the matrix A if UPLO = 'U',
 *          or the number of subdiagonals if UPLO = 'L'.  KD >= 0.
 *
 *  AB      (input/output) DOUBLE PRECISION array, dimension (LDAB,N)
 *          On entry, the upper or lower triangle of the symmetric band
 *          matrix A, stored in the first KD+1 rows of the array.  The
 *          j-th column of A is stored in the j-th column of the array AB
 *          as follows:
 *          if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;
 *          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).
 *          On exit, the diagonal elements of AB are overwritten by the
 *          diagonal elements of the tridiagonal matrix T; if KD > 0, the
 *          elements on the first superdiagonal (if UPLO = 'U') or the
 *          first subdiagonal (if UPLO = 'L') are overwritten by the
 *          off-diagonal elements of T; the rest of AB is overwritten by
 *          values generated during the reduction.
 *
 *  LDAB    (input) INTEGER
 *          The leading dimension of the array AB.  LDAB >= KD+1.
 *
 *  D       (output) DOUBLE PRECISION array, dimension (N)
 *          The diagonal elements of the tridiagonal matrix T.
 *
 *  E       (output) DOUBLE PRECISION array, dimension (N-1)
 *          The off-diagonal elements of the tridiagonal matrix T:
 *          E(i) = T(i,i+1) if UPLO = 'U'; E(i) = T(i+1,i) if UPLO = 'L'.
 *
 *  Q       (input/output) DOUBLE PRECISION array, dimension (LDQ,N)
 *          On entry, if VECT = 'U', then Q must contain an N-by-N
 *          matrix X; if VECT = 'N' or 'V', then Q need not be set.
 *
 *          On exit:
 *          if VECT = 'V', Q contains the N-by-N orthogonal matrix Q;
 *          if VECT = 'U', Q contains the product X*Q;
 *          if VECT = 'N', the array Q is not referenced.
 *
 *  LDQ     (input) INTEGER
 *          The leading dimension of the array Q.
 *          LDQ >= 1, and LDQ >= N if VECT = 'V' or 'U'.
 *
 *  WORK    (workspace) DOUBLE PRECISION array, dimension (N)
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit
 *          < 0:  if INFO = -i, the i-th argument had an illegal value
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Dsbtrd()

dsbtrd(String, String, int, int, double[], int, int, double[], int, double[], int, double[], int, int, double[], int, intW)

 public Dsbtrd()

 public static void dsbtrd(String vect,
                           String uplo,
                           int n,
                           int kd,
                           double ab[],
                           int _ab_offset,
                           int ldab,
                           double d[],
                           int _d_offset,
                           double e[],
                           int _e_offset,
                           double q[],
                           int _q_offset,
                           int ldq,
                           double work[],
                           int _work_offset,
                           intW info)

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