edu.emory.mathcs.csparsej.tdouble

Class Dcs_house

java.lang.Object

edu.emory.mathcs.csparsej.tdouble.Dcs_house

public class Dcs_house
extends java.lang.Object

Compute Householder reflection.

Constructor Summary

Constructors

Constructor and Description
Dcs_house()

Method Summary

Modifier and Type	Method and Description
static double	cs_house(double[] x, int x_offset, double[] beta, int n) Compute a Householder reflection, overwrite x with v, where (I-beta*v*v')*x = s*e1.

Methods inherited from class java.lang.Object

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

Constructor Detail

Dcs_house

public Dcs_house()

Method Detail

cs_house

public static double cs_house(double[] x,
                              int x_offset,
                              double[] beta,
                              int n)

Compute a Householder reflection, overwrite x with v, where (I-beta*v*v')*x = s*e1. See Algo 5.1.1, Golub & Van Loan, 3rd ed.

Parameters:

x - x on output, v on input

x_offset - the index of the first element in array x

beta - scalar beta

n - the length of x

Returns:

norm2(x), -1 on error