fr.cnes.sirius.patrius.stela

Class JavaMathAdapter

java.lang.Object

fr.cnes.sirius.patrius.stela.JavaMathAdapter

public final class JavaMathAdapter
extends Object

Math adapter class.

Since:

1.3

Version:

$Id: JavaMathAdapter.java 18397 2017-11-20 08:11:35Z bignon $

Author:

cardosop

Concurrency :

unconditionally thread-safe

Method Summary

Methods

Modifier and Type	Method and Description
static double	binomialCoefficientGeneric(int a, int b) Compute the Binomial Coefficient, "a choose b", the number of b-element subsets that can be selected from an a-element set.
static double[][]	matrixAdd(double[][] m1, double[][] m2) Add 2 matrices.
static double[][]	matrixMultiply(double[][] m1, double[][] m2) Multiply 2 matrix.
static void	matrixToVector(double[][] matrix, double[] vector, int offset) Copy a matrix into a vector, column per column.
static double[][]	matrixTranspose(double[][] m) Transpose a matrix.
static double[]	matrixVectorMultiply(double[][] m, double[] v) Multiply matrix with a vector.
static double	mod(double x, double mod) Computes "x" modulo "mod".
static double[]	negate(double[] v) Invert a vector.
static double[][]	scalarMultiply(double coef, double[][] matrix) Return coef * matrix.
static double[][]	threeDMatrixVectorMultiply(double[][][] mat, double[] vect) Multiply an automatically-generated-3-dimensional matrix with a vector. Automatically generated 3D matrices have their rows and wideness inverted.
static void	vectorToMatrix(double[] vector, double[][] matrix) Copy a vector into a matrix, column per column.

Methods inherited from class java.lang.Object

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

Method Detail

mod

public static double mod(double x,
         double mod)

Computes "x" modulo "mod".

Parameters:

x - value to modulate

mod - modulo (for instance π)

Returns:

"x" modulo "mod"

binomialCoefficientGeneric

public static double binomialCoefficientGeneric(int a,
                                int b)

Compute the Binomial Coefficient, "a choose b", the number of b-element subsets that can be selected from an a-element set. This formula can be used with negative a values.

Parameters:

a - the size of the set

b - the size of the subsets

Returns:

a choose b

threeDMatrixVectorMultiply

public static double[][] threeDMatrixVectorMultiply(double[][][] mat,
                                    double[] vect)
                                             throws PatriusException

Multiply an automatically-generated-3-dimensional matrix with a vector.
Automatically generated 3D matrices have their rows and wideness inverted. This method corrects it.

Parameters:

mat - the 3-dimensional matrix

vect - the vector

Returns:

product, a 2-dimensional matrix

Throws:

PatriusException - thrown if matrix dimension mismatch

negate

public static double[] negate(double[] v)

Invert a vector.

Parameters:

v - vector

Returns:

-v

matrixAdd

public static double[][] matrixAdd(double[][] m1,
                   double[][] m2)
                            throws PatriusException

Add 2 matrices.

Parameters:

m1 - first matrix

m2 - second matrix

Returns:

sum of the two matrices

Throws:

PatriusException - thrown if matrix dimension mismatch

vectorToMatrix

public static void vectorToMatrix(double[] vector,
                  double[][] matrix)

Copy a vector into a matrix, column per column.

Parameters:

vector - vector to be copied

matrix - matrix where to put the data

matrixToVector

public static void matrixToVector(double[][] matrix,
                  double[] vector,
                  int offset)

Copy a matrix into a vector, column per column.

Parameters:

matrix - matrix from which the data is read

vector - vector in which the data is put

offset - offset after which the data will be put in the vector thrown if dimensions mismatch

matrixMultiply

public static double[][] matrixMultiply(double[][] m1,
                        double[][] m2)

Multiply 2 matrix.

Parameters:

m1 - first Matrix

m2 - second matrix

Returns:

the products

matrixTranspose

public static double[][] matrixTranspose(double[][] m)

Transpose a matrix.

Parameters:

m - the matrix.

Returns:

Matrix transposed.

matrixVectorMultiply

public static double[] matrixVectorMultiply(double[][] m,
                            double[] v)

Multiply matrix with a vector.

Parameters:

m - the matrix

v - the vector

Returns:

Products with matrix and vector

scalarMultiply

public static double[][] scalarMultiply(double coef,
                        double[][] matrix)

Return coef * matrix.

Parameters:

coef - a coefficent

matrix - a matrix

Returns:

a matrix resulting from the operation coef * matrix.