gov.sns.tools
Class ArrayMath

java.lang.Object
  |
  +--gov.sns.tools.ArrayMath

public class ArrayMath

extends java.lang.Object

Provide some simple array math operations.

Constructor Summary

protected

ArrayMath() Creates a new instance of ArrayMath

Method Summary

static double[]	elementProduct(double[] vec1, double[] vec2) Multiply two vectors element by element: m(i) = v1(i) * v2(i)
static java.lang.Object	elementProduct(java.lang.Object vec1, java.lang.Object vec2, int[] dimensions) Return the square root of each element: m(i1,i2,...) = v1(i1,i2,...) * v2(i1,i2,...)
static double[]	elementSquareRoot(double[] vector) Return the square root of each element: s(i) = squar_root( vec(i) )
static java.lang.Object	elementSquareRoot(java.lang.Object vector, int[] dimensions) Return the square root of each element: s(i1,i2,...) = squar_root( vec(i1,i2,...) )
static java.lang.Object	elementSquareRootAbs(java.lang.Object vector, int[] dimensions) Return the square root of each element: s(i1,i2,...) = squar_root( abs( vec(i1,i2,...) ) )
static double[][]	matrixProduct(double[] columnVector, double[] rowVector) Multiply a column vector by a row vector where the product is a matrix defined by: M(i,j) = columnVector(i) * rowVector(j) Note: This is not a scalar product, nor a vector product, but rather it is a product of a column vector with a row vector which results in a matrix.
static double[]	multiply(double[][] matrix, double[] vector) Multiply a vector by a matrix defined by: v(i) = Sumj( mat(i,j) * vec(j) )
static double[]	multiply(double[] vector, double scalar) Multiply a vector by a scalar: v(i) = vector(i) * scalar
static java.lang.Object	multiply(java.lang.Object vector, double scalar, int[] dimensions) Return the square root of each element: m(i1,i2,...) = v(i1,i2,...) * scalar
static double	scalarProduct(double[] vec1, double[] vec2) Calculate the scalar product of two vectors.
static double[][]	subtract(double[][] mat1, double[][] mat2) Subtract two matrices M(i,j) = m1(i,j) - m2(i,j)
static double[]	subtract(double[] vec1, double[] vec2) Subtract two vectors v(i) = v1(i) - v2(i)
static java.lang.Object	subtract(java.lang.Object vec1, java.lang.Object vec2, int[] dimensions) Return the square root of each element: s(i1,i2,...) = v1(i1,i2,...) - v2(i1,i2,...)
static double[]	transform(double[] array, double scale, double offset) Transform an array by mutlitplying by a scale and adding an offset v(i) = scale * array(i) + offset
static double[]	translate(double[] array, double offset) Add a scalar to each element of an array v(i) = array(i) + offset

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayMath

protected ArrayMath()

Creates a new instance of ArrayMath

Method Detail

translate

public static double[] translate(double[] array,
                                 double offset)

Add a scalar to each element of an array v(i) = array(i) + offset

transform

public static double[] transform(double[] array,
                                 double scale,
                                 double offset)

Transform an array by mutlitplying by a scale and adding an offset v(i) = scale * array(i) + offset

subtract

public static double[] subtract(double[] vec1,
                                double[] vec2)

Subtract two vectors v(i) = v1(i) - v2(i)

subtract

public static double[][] subtract(double[][] mat1,
                                  double[][] mat2)

Subtract two matrices M(i,j) = m1(i,j) - m2(i,j)

subtract

public static java.lang.Object subtract(java.lang.Object vec1,
                                        java.lang.Object vec2,
                                        int[] dimensions)

Return the square root of each element: s(i1,i2,...) = v1(i1,i2,...) - v2(i1,i2,...)

multiply

public static double[] multiply(double[] vector,
                                double scalar)

Multiply a vector by a scalar: v(i) = vector(i) * scalar

multiply

public static java.lang.Object multiply(java.lang.Object vector,
                                        double scalar,
                                        int[] dimensions)

Return the square root of each element: m(i1,i2,...) = v(i1,i2,...) * scalar

multiply

public static double[] multiply(double[][] matrix,
                                double[] vector)

Multiply a vector by a matrix defined by: v(i) = Sum_j( mat(i,j) * vec(j) )

scalarProduct

public static double scalarProduct(double[] vec1,
                                   double[] vec2)

Calculate the scalar product of two vectors.

matrixProduct

public static double[][] matrixProduct(double[] columnVector,
                                       double[] rowVector)

Multiply a column vector by a row vector where the product is a matrix defined by: M(i,j) = columnVector(i) * rowVector(j) Note: This is not a scalar product, nor a vector product, but rather it is a product of a column vector with a row vector which results in a matrix.

elementProduct

public static java.lang.Object elementProduct(java.lang.Object vec1,
                                              java.lang.Object vec2,
                                              int[] dimensions)

Return the square root of each element: m(i1,i2,...) = v1(i1,i2,...) * v2(i1,i2,...)

elementProduct

public static double[] elementProduct(double[] vec1,
                                      double[] vec2)

Multiply two vectors element by element: m(i) = v1(i) * v2(i)

elementSquareRoot

public static double[] elementSquareRoot(double[] vector)

Return the square root of each element: s(i) = squar_root( vec(i) )

elementSquareRoot

public static java.lang.Object elementSquareRoot(java.lang.Object vector,
                                                 int[] dimensions)

Return the square root of each element: s(i1,i2,...) = squar_root( vec(i1,i2,...) )

elementSquareRootAbs

public static java.lang.Object elementSquareRootAbs(java.lang.Object vector,
                                                    int[] dimensions)

Return the square root of each element: s(i1,i2,...) = squar_root( abs( vec(i1,i2,...) ) )