DSBTRDRun Method

public void Run(
	string VECT,
	string UPLO,
	int N,
	int KD,
	ref double[] AB,
	int offset_ab,
	int LDAB,
	ref double[] D,
	int offset_d,
	ref double[] E,
	int offset_e,
	ref double[] Q,
	int offset_q,
	int LDQ,
	ref double[] WORK,
	int offset_work,
	ref int INFO
)

Public Sub Run ( 
	VECT As String,
	UPLO As String,
	N As Integer,
	KD As Integer,
	ByRef AB As Double(),
	offset_ab As Integer,
	LDAB As Integer,
	ByRef D As Double(),
	offset_d As Integer,
	ByRef E As Double(),
	offset_e As Integer,
	ByRef Q As Double(),
	offset_q As Integer,
	LDQ As Integer,
	ByRef WORK As Double(),
	offset_work As Integer,
	ByRef INFO As Integer
)

Parameters

VECT  String

(input) CHARACTER*1 = 'N': do not form Q; = 'V': form Q; = 'U': update a matrix X, by forming X*Q.

UPLO  String

(input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored.

N  Int32

(input) INTEGER The order of the matrix A. N .GE. 0.

KD  Int32

(input) INTEGER The number of superdiagonals of the matrix A if UPLO = 'U', or the number of subdiagonals if UPLO = 'L'. KD .GE. 0.

AB  Double

(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).LE.i.LE.j; if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j.LE.i.LE.min(n,j+kd). On exit, the diagonal elements of AB are overwritten by the diagonal elements of the tridiagonal matrix T; if KD .GT. 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.

offset_ab  Int32

 

LDAB  Int32

(input) INTEGER The leading dimension of the array AB. LDAB .GE. KD+1.

D  Double

(output) DOUBLE PRECISION array, dimension (N) The diagonal elements of the tridiagonal matrix T.

offset_d  Int32

 

E  Double

(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'.

offset_e  Int32

 

Q  Double

(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.

offset_q  Int32

 

LDQ  Int32

(input) INTEGER The leading dimension of the array Q. LDQ .GE. 1, and LDQ .GE. N if VECT = 'V' or 'U'.

WORK  Double

(workspace) DOUBLE PRECISION array, dimension (N)

offset_work  Int32

 

INFO  Int32

(output) INTEGER = 0: successful exit .LT. 0: if INFO = -i, the i-th argument had an illegal value

Reference