jmathlib.toolbox.jmathlib.matrix._private.Jampack
Class House

java.lang.Object
  extended by jmathlib.toolbox.jmathlib.matrix._private.Jampack.House

public class House
extends java.lang.Object

House provides static methods to generate and apply Householder transformations.

Version:
Pre-alpha
Author:
G. W. Stewart

Constructor Summary
House()
           
 
Method Summary
static Zmat au(Zmat A, Z1 u, int r1, int r2, int c1, int c2)
          Postmultiplies the Householder transformation contained in a Z1 into a Zmat A[r1:r2,c1:c2] and overwrites Zmat A[r1:r2,c1:c2] with the results.
static Zmat au(Zmat A, Z1 u, int r1, int r2, int c1, int c2, Z1 v)
          Postmultiplies the Householder transformation contained in a Z1 into a Zmat A[r1:r2,c1:c2] and overwrites Zmat A[r1:r2,c1:c2] with the results.
static Z1 genc(Zmat A, int r1, int r2, int c)
          Generates a Householder transformation from within the part of column c of a Zmat (altered) extending from rows r1 to r2.
static Z1 genr(Zmat A, int r, int c1, int c2)
          Generates a Householder transformation from within the part of row r of a Zmat (altered) extending from columns c1 to c2.
static Zmat ua(Z1 u, Zmat A, int r1, int r2, int c1, int c2)
          Premultiplies the Householder transformation contained in a Z1 into a Zmat A[r1:r2,c1:c2] and overwrites Zmat A[r1:r2,c1:c2] with the results.
static Zmat ua(Z1 u, Zmat A, int r1, int r2, int c1, int c2, Z1 v)
          Premultiplies the Householder transformation contained in a Z1 into a Zmat A[r1:r2,c1:c2] and overwrites Zmat A[r1:r2,c1:c2] with the results.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

House

public House()
Method Detail

genc

public static Z1 genc(Zmat A,
                      int r1,
                      int r2,
                      int c)
               throws JampackException
Generates a Householder transformation from within the part of column c of a Zmat (altered) extending from rows r1 to r2. The method overwrites the column with the result of applying the transformation.

Parameters:
A - The matrix from which the transformation is to be generated (altered)
r1 - The index of the row in which the generating column begins
r2 - The index of the row in which the generating column ends
c - The index of the generating column
Returns:
A Z1 of length r2-r1+1 containing the Householder vector
Throws:
JampackException - Passed from below.

genr

public static Z1 genr(Zmat A,
                      int r,
                      int c1,
                      int c2)
               throws JampackException
Generates a Householder transformation from within the part of row r of a Zmat (altered) extending from columns c1 to c2. The method overwrites the row with the result of applying the transformation.

Parameters:
A - The matrix from which the transformation is to be generated (altered)
r - The index of the generating row
c1 - The index of the column in which the generating row begins
c2 - The index of the column in which the generating row ends
Returns:
A Z1 of length r2-r1+1 containing the Householder vector
Throws:
JampackException - Passed from below.

ua

public static Zmat ua(Z1 u,
                      Zmat A,
                      int r1,
                      int r2,
                      int c1,
                      int c2,
                      Z1 v)
               throws JampackException
Premultiplies the Householder transformation contained in a Z1 into a Zmat A[r1:r2,c1:c2] and overwrites Zmat A[r1:r2,c1:c2] with the results. If r1 > r2 or c1 > c2 the method does nothing.

Parameters:
u - The Householder vector
A - The Zmat to which the transformation is to be applied (altered)
r1 - The index of the first row to which the transformation is to be applied
r2 - The index of the last row to which the transformation is to be applied
c1 - The index of the first column to which the transformation is index of the to be applied
c2 - The index of the last column to which the transformation is to be applied
v - A work array of length at least c2-c1+1
Returns:
The transformed Zmat A
Throws:
JampackException - Thrown if either u or v is too short.

ua

public static Zmat ua(Z1 u,
                      Zmat A,
                      int r1,
                      int r2,
                      int c1,
                      int c2)
               throws JampackException
Premultiplies the Householder transformation contained in a Z1 into a Zmat A[r1:r2,c1:c2] and overwrites Zmat A[r1:r2,c1:c2] with the results. If r1 > r2 or c1 > c2 the method does nothing.

Parameters:
u - The Householder vector
A - The Zmat to which the transformation is to be applied (altered)
r1 - The index of the first row to which the transformation is to be applied
r2 - The index of the last row to which the transformation is to be applied
c1 - The index of the first column to which the transformation is index of the to be applied
c2 - The index of the last column to which the transformation is to be applied
Returns:
The transformed Zmat A
Throws:
JampackException - Passed from below.

au

public static Zmat au(Zmat A,
                      Z1 u,
                      int r1,
                      int r2,
                      int c1,
                      int c2,
                      Z1 v)
               throws JampackException
Postmultiplies the Householder transformation contained in a Z1 into a Zmat A[r1:r2,c1:c2] and overwrites Zmat A[r1:r2,c1:c2] with the results. If r1 > r2 or c1 > c2 the method does nothing.

Parameters:
u - The Householder vector
A - The Zmat to which the transformation is to be applied (altered)
r1 - The index of the first row to which the transformation is to be applied
r2 - The index of the last row to which the transformation is to be applied
c1 - The index of the first column to which the transformation is index of the to be applied
c2 - The index of the last column to which the transformation is to be applied
v - A work array of length at least c2-c1+1
Returns:
The transformed Zmat A
Throws:
JampackException - Thrown if either u or v is too short.

au

public static Zmat au(Zmat A,
                      Z1 u,
                      int r1,
                      int r2,
                      int c1,
                      int c2)
               throws JampackException
Postmultiplies the Householder transformation contained in a Z1 into a Zmat A[r1:r2,c1:c2] and overwrites Zmat A[r1:r2,c1:c2] with the results. If r1 > r2 or c1 > c2 the method does nothing.

Parameters:
u - The Householder vector
A - The Zmat to which the transformation is to be applied (altered)
r1 - The index of the first row to which the transformation is to be applied
r2 - The index of the last row to which the transformation is to be applied
c1 - The index of the first column to which the transformation is index of the to be applied
c2 - The index of the last column to which the transformation is to be applied
Returns:
The transformed Zmat A
Throws:
JampackException - Passed from below.

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