HMatrix (LCSim 3.1.7 API)

java.lang.Object
- org.lcsim.recon.emid.hmatrix.HMatrix

All Implemented Interfaces:

Serializable
```
public class HMatrix
extends Object
implements Serializable
```
This class allows one to calculate how well a measurement agrees with expectations. The vector of average values and the associated covariance matrix is used to construct the HMatrix. The degree of agreement is calculated as a chi-squared of a measurement vector against the expectations. The covariance matrix is defined as:

M_ij = 1
N
N

n = 1
(E_i⁽ⁿ⁾ -

E

i
)(E_j⁽ⁿ⁾ -

E

j
)

The H(essian)Matrix is the inverse of the covariance matrix. The chi-squared is then calculated via

z_m N

i,j = 1
(E_i^(m) -

E

i
)H_ij (E_j^(m) -

E

j
)

Methods to persist the HMatrix are provided in both plain ASCII format and Java serialized format.

Version:

$Id: HMatrix.java,v 1.7 2012/08/08 00:06:33 jeremy Exp $

Author:

Norman A. Graf

See Also:
Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`private double[]`	`_cov`
`private int`	`_dim`
`private double[][]`	`_invcov`
`private int`	`_key`
`private double[]`	`_tmp`
`private double[]`	`_tmp2`
`private double[]`	`_vec`

Constructor Summary

Constructors
Constructor and Description
`HMatrix()`
`HMatrix(int dim, int key, double[] vec, double[] cov, double[][] invcov)` Constructor
`HMatrix(String resourceFileName)`

Method Summary

Methods
Modifier and Type	Method and Description
`double[]`	`averageVector()` Return the vector of averages
`double`	`chisquared(double[] dat)` Calculates the chi-squared for the measurement compared to the expected values and covariances represented by the HMatrix.
`double`	`chisquaredDiagonal(double[] dat)` Calculates the diagonal chi-squared for the measurement compared to the expected values and covariances represented by the HMatrix, neglecting correlations.
`private static HMatrix`	`create(BufferedReader bufferedreader)`
`static HMatrix`	`create(InputStream in)`
`double[]`	`packedInverseCovarianceMatrix()` Return the inverse covariance matrix packed in lower-diagonal form
`static HMatrix`	`read(Reader reader)` Reads the HMatrix from a Reader
`static HMatrix`	`read(String filename)` Reads the HMatrix from an ASCII file
`String`	`toString()` Output stream
`void`	`write(String filename, String comment)` Writes out the HMatrix to an ASCII file

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - _invcov
```
private double[][] _invcov
```
  - _vec
```
private double[] _vec
```
  - _cov
```
private double[] _cov
```
  - _dim
```
private int _dim
```
  - _key
```
private int _key
```
  - _tmp
```
private double[] _tmp
```
  - _tmp2
```
private double[] _tmp2
```
- Constructor Detail
  - HMatrix
```
public HMatrix()
```
  - HMatrix
```
public HMatrix(int dim,
       int key,
       double[] vec,
       double[] cov,
       double[][] invcov)
```
    Constructor
    
    Parameters:
    dim - the dimensionality of the matrix
    key - the key for indexing this HMatrix
    vec - The array of average values for the measurement space.
    cov - The inverse of the covariance matrix for the averages.
  - HMatrix
```
public HMatrix(String resourceFileName)
```
- Method Detail
  - chisquared
```
public double chisquared(double[] dat)
```
    Calculates the chi-squared for the measurement compared to the expected values and covariances represented by the HMatrix.
    
    Parameters:
    dat - The array of measured values
    
    Returns:
    The value of chi-squared.
  - chisquaredDiagonal
```
public double chisquaredDiagonal(double[] dat)
```
    Calculates the diagonal chi-squared for the measurement compared to the expected values and covariances represented by the HMatrix, neglecting correlations.
    
    Parameters:
    dat - The array of measured values
    
    Returns:
    The value of the diagonal chi-squared.
  - toString
```
public String toString()
```
    Output stream
    
    Overrides:
    
    toString in class Object
    
    Returns:
    A String representation of the object.
  - averageVector
```
public double[] averageVector()
```
    Return the vector of averages
    
    Returns:
    the measurement vector averages
  - packedInverseCovarianceMatrix
```
public double[] packedInverseCovarianceMatrix()
```
    Return the inverse covariance matrix packed in lower-diagonal form
    
    Returns:
    the inverse covariance matrix packed in lower-diagonal form
  - write
```
public void write(String filename,
         String comment)
```
    Writes out the HMatrix to an ASCII file
  - read
```
public static HMatrix read(String filename)
```
    Reads the HMatrix from an ASCII file
  - read
```
public static HMatrix read(Reader reader)
```
    Reads the HMatrix from a Reader
  - create
```
public static HMatrix create(InputStream in)
```
  - create
```
private static HMatrix create(BufferedReader bufferedreader)
                       throws IOException
```
    Throws:
    
    IOException

Class HMatrix

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_invcov

_vec

_cov

_dim

_key

_tmp

_tmp2

Constructor Detail

HMatrix

HMatrix

HMatrix

Method Detail

chisquared

chisquaredDiagonal

toString

averageVector

packedInverseCovarianceMatrix

write

read

read

create

create