Example usage for org.apache.commons.math3.linear ArrayRealVector ArrayRealVector

Introduction

In this page you can find the example usage for org.apache.commons.math3.linear ArrayRealVector ArrayRealVector.

Prototype

public ArrayRealVector(double[] v1, double[] v2)

Source Link

Document

Construct a vector by appending one vector to another vector.

Usage

From source file:org.lambda3.indra.util.VectorIterator.java

public RealVector readDenseVector(int dimensions) throws IOException {
    double[] vector = new double[dimensions];

    for (int i = 0; i < dimensions; i++) {
        vector[i] = (double) input.readFloat();
    }//from w w w.  j a  v a 2s  .  com

    return new ArrayRealVector(vector, false);
}

From source file:org.meteoinfo.math.linalg.LinalgUtil.java

/**
 * Solve a linear matrix equation, or system of linear scalar equations.
 * @param a Coefficient matrix.//w  w  w .  j  a  va 2  s .  c  o m
 * @param b Ordinate or dependent variable? values.
 * @return Solution to the system a x = b. Returned shape is identical to b.
 */
public static Array solve(Array a, Array b) {
    Array r = Array.factory(DataType.DOUBLE, b.getShape());
    double[][] aa = (double[][]) ArrayUtil.copyToNDJavaArray(a);
    RealMatrix coefficients = new Array2DRowRealMatrix(aa, false);
    DecompositionSolver solver = new LUDecomposition(coefficients).getSolver();
    double[] bb = (double[]) ArrayUtil.copyToNDJavaArray(b);
    RealVector constants = new ArrayRealVector(bb, false);
    RealVector solution = solver.solve(constants);
    for (int i = 0; i < r.getSize(); i++) {
        r.setDouble(i, solution.getEntry(i));
    }

    return r;
}