org.netlib.lapack
Class SLASD3
java.lang.Object
org.netlib.lapack.SLASD3
public class SLASD3
- extends java.lang.Object
SLASD3 is a simplified interface to the JLAPACK routine slasd3.
This interface converts Java-style 2D row-major arrays into
the 1D column-major linearized arrays expected by the lower
level JLAPACK routines. Using this interface also allows you
to omit offset and leading dimension arguments. However, because
of these conversions, these routines will be slower than the low
level ones. Following is the description from the original Fortran
source. Contact seymour@cs.utk.edu with any questions.
* ..
*
* Purpose
* =======
*
* SLASD3 finds all the square roots of the roots of the secular
* equation, as defined by the values in D and Z. It makes the
* appropriate calls to SLASD4 and then updates the singular
* vectors by matrix multiplication.
*
* This code 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 XMP, Cray YMP, Cray C 90, or Cray 2.
* It could conceivably fail on hexadecimal or decimal machines
* without guard digits, but we know of none.
*
* SLASD3 is called from SLASD1.
*
* Arguments
* =========
*
* NL (input) INTEGER
* The row dimension of the upper block. NL >= 1.
*
* NR (input) INTEGER
* The row dimension of the lower block. NR >= 1.
*
* SQRE (input) INTEGER
* = 0: the lower block is an NR-by-NR square matrix.
* = 1: the lower block is an NR-by-(NR+1) rectangular matrix.
*
* The bidiagonal matrix has N = NL + NR + 1 rows and
* M = N + SQRE >= N columns.
*
* K (input) INTEGER
* The size of the secular equation, 1 =< K = < N.
*
* D (output) REAL array, dimension(K)
* On exit the square roots of the roots of the secular equation,
* in ascending order.
*
* Q (workspace) REAL array,
* dimension at least (LDQ,K).
*
* LDQ (input) INTEGER
* The leading dimension of the array Q. LDQ >= K.
*
* DSIGMA (input) REAL array, dimension(K)
* The first K elements of this array contain the old roots
* of the deflated updating problem. These are the poles
* of the secular equation.
*
* U (input) REAL array, dimension (LDU, N)
* The last N - K columns of this matrix contain the deflated
* left singular vectors.
*
* LDU (input) INTEGER
* The leading dimension of the array U. LDU >= N.
*
* U2 (input) REAL array, dimension (LDU2, N)
* The first K columns of this matrix contain the non-deflated
* left singular vectors for the split problem.
*
* LDU2 (input) INTEGER
* The leading dimension of the array U2. LDU2 >= N.
*
* VT (input) REAL array, dimension (LDVT, M)
* The last M - K columns of VT' contain the deflated
* right singular vectors.
*
* LDVT (input) INTEGER
* The leading dimension of the array VT. LDVT >= N.
*
* VT2 (input) REAL array, dimension (LDVT2, N)
* The first K columns of VT2' contain the non-deflated
* right singular vectors for the split problem.
*
* LDVT2 (input) INTEGER
* The leading dimension of the array VT2. LDVT2 >= N.
*
* IDXC (input) INTEGER array, dimension ( N )
* The permutation used to arrange the columns of U (and rows of
* VT) into three groups: the first group contains non-zero
* entries only at and above (or before) NL +1; the second
* contains non-zero entries only at and below (or after) NL+2;
* and the third is dense. The first column of U and the row of
* VT are treated separately, however.
*
* The rows of the singular vectors found by SLASD4
* must be likewise permuted before the matrix multiplies can
* take place.
*
* CTOT (input) INTEGER array, dimension ( 4 )
* A count of the total number of the various types of columns
* in U (or rows in VT), as described in IDXC. The fourth column
* type is any column which has been deflated.
*
* Z (input) REAL array, dimension (K)
* The first K elements of this array contain the components
* of the deflation-adjusted updating row vector.
*
* INFO (output) INTEGER
* = 0: successful exit.
* < 0: if INFO = -i, the i-th argument had an illegal value.
* > 0: if INFO = 1, an singular value did not converge
*
* Further Details
* ===============
*
* Based on contributions by
* Ming Gu and Huan Ren, Computer Science Division, University of
* California at Berkeley, USA
*
* =====================================================================
*
* .. Parameters ..
|
Method Summary |
static void |
SLASD3(int nl,
int nr,
int sqre,
int k,
float[] d,
float[][] q,
float[] dsigma,
float[][] u,
float[][] u2,
float[][] vt,
float[][] vt2,
int[] idxc,
int[] ctot,
float[] z,
intW info)
|
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
SLASD3
public SLASD3()
SLASD3
public static void SLASD3(int nl,
int nr,
int sqre,
int k,
float[] d,
float[][] q,
float[] dsigma,
float[][] u,
float[][] u2,
float[][] vt,
float[][] vt2,
int[] idxc,
int[] ctot,
float[] z,
intW info)