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DLASD3Run Method

Purpose ======= DLASD3 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 DLASD4 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. DLASD3 is called from DLASD1.

Namespace: DotNumerics.LinearAlgebra.CSLapack
Assembly: DWSIM.MathOps.DotNumerics (in DWSIM.MathOps.DotNumerics.dll) Version: 1.0.0.0 (1.0.0.0)
Syntax
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public void Run(
	int NL,
	int NR,
	int SQRE,
	int K,
	ref double[] D,
	int offset_d,
	ref double[] Q,
	int offset_q,
	int LDQ,
	ref double[] DSIGMA,
	int offset_dsigma,
	ref double[] U,
	int offset_u,
	int LDU,
	double[] U2,
	int offset_u2,
	int LDU2,
	ref double[] VT,
	int offset_vt,
	int LDVT,
	ref double[] VT2,
	int offset_vt2,
	int LDVT2,
	int[] IDXC,
	int offset_idxc,
	int[] CTOT,
	int offset_ctot,
	ref double[] Z,
	int offset_z,
	ref int INFO
)
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Parameters

NL  Int32
(input) INTEGER The row dimension of the upper block. NL .GE. 1.
NR  Int32
(input) INTEGER The row dimension of the lower block. NR .GE. 1.
SQRE  Int32
(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 .GE. N columns.
K  Int32
(input) INTEGER The size of the secular equation, 1 =.LT. K = .LT. N.
D  Double
(output) DOUBLE PRECISION array, dimension(K) On exit the square roots of the roots of the secular equation, in ascending order.
offset_d  Int32
 
Q  Double
(workspace) DOUBLE PRECISION array, dimension at least (LDQ,K).
offset_q  Int32
 
LDQ  Int32
(input) INTEGER The leading dimension of the array Q. LDQ .GE. K.
DSIGMA  Double
(input) DOUBLE PRECISION 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.
offset_dsigma  Int32
 
U  Double
(output) DOUBLE PRECISION array, dimension (LDU, N) The last N - K columns of this matrix contain the deflated left singular vectors.
offset_u  Int32
 
LDU  Int32
(input) INTEGER The leading dimension of the array U. LDU .GE. N.
U2  Double
(input/output) DOUBLE PRECISION array, dimension (LDU2, N) The first K columns of this matrix contain the non-deflated left singular vectors for the split problem.
offset_u2  Int32
 
LDU2  Int32
(input) INTEGER The leading dimension of the array U2. LDU2 .GE. N.
VT  Double
(output) DOUBLE PRECISION array, dimension (LDVT, M) The last M - K columns of VT' contain the deflated right singular vectors.
offset_vt  Int32
 
LDVT  Int32
(input) INTEGER The leading dimension of the array VT. LDVT .GE. N.
VT2  Double
(input/output) DOUBLE PRECISION array, dimension (LDVT2, N) The first K columns of VT2' contain the non-deflated right singular vectors for the split problem.
offset_vt2  Int32
 
LDVT2  Int32
(input) INTEGER The leading dimension of the array VT2. LDVT2 .GE. N.
IDXC  Int32
(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 DLASD4 must be likewise permuted before the matrix multiplies can take place.
offset_idxc  Int32
 
CTOT  Int32
(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.
offset_ctot  Int32
 
Z  Double
(input) DOUBLE PRECISION array, dimension (K) The first K elements of this array contain the components of the deflation-adjusted updating row vector.
offset_z  Int32
 
INFO  Int32
(output) INTEGER = 0: successful exit. .LT. 0: if INFO = -i, the i-th argument had an illegal value. .GT. 0: if INFO = 1, an singular value did not converge
See Also