Example usage for org.apache.commons.math3.linear RealMatrix setEntry

List of usage examples for org.apache.commons.math3.linear RealMatrix setEntry

Introduction

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

Prototype

void setEntry(int row, int column, double value) throws OutOfRangeException;

Source Link

Document

Set the entry in the specified row and column.

Usage

From source file:org.lenskit.mf.MFModel.java

private void readObject(ObjectInputStream input) throws IOException, ClassNotFoundException {
    featureCount = input.readInt();/* w w  w.  ja v a 2s  .  c om*/
    userCount = input.readInt();
    itemCount = input.readInt();

    RealMatrix umat = MatrixUtils.createRealMatrix(userCount, featureCount);
    for (int i = 0; i < userCount; i++) {
        for (int j = 0; j < featureCount; j++) {
            umat.setEntry(i, j, input.readDouble());
        }
    }
    userMatrix = umat;

    RealMatrix imat = MatrixUtils.createRealMatrix(itemCount, featureCount);
    for (int i = 0; i < itemCount; i++) {
        for (int j = 0; j < featureCount; j++) {
            imat.setEntry(i, j, input.readDouble());
        }
    }
    itemMatrix = imat;

    userIndex = (KeyIndex) input.readObject();
    itemIndex = (KeyIndex) input.readObject();

    if (userIndex.size() != userMatrix.getRowDimension()) {
        throw new InvalidObjectException("user matrix and index have different row counts");
    }
    if (itemIndex.size() != itemMatrix.getRowDimension()) {
        throw new InvalidObjectException("item matrix and index have different row counts");
    }
}

From source file:org.lenskit.pf.HPFModelProvider.java

@Override
public HPFModel get() {

    final int userNum = ratings.getUserIndex().size();
    final int itemNum = ratings.getItemIndex().size();
    final int featureCount = hyperParameters.getFeatureCount();
    final double a = hyperParameters.getUserWeightShpPrior();
    final double aPrime = hyperParameters.getUserActivityShpPrior();
    final double bPrime = hyperParameters.getUserActivityPriorMean();
    final double c = hyperParameters.getItemWeightShpPrior();
    final double cPrime = hyperParameters.getItemActivityShpPrior();
    final double dPrime = hyperParameters.getItemActivityPriorMean();
    final double kappaShpU = aPrime + featureCount * a;
    final double tauShpI = cPrime + featureCount * c;

    RealMatrix gammaShp = MatrixUtils.createRealMatrix(userNum, featureCount);
    RealMatrix gammaRte = MatrixUtils.createRealMatrix(userNum, featureCount);
    RealVector kappaShp = MatrixUtils.createRealVector(new double[userNum]);
    RealVector kappaRte = MatrixUtils.createRealVector(new double[userNum]);
    RealMatrix lambdaShp = MatrixUtils.createRealMatrix(itemNum, featureCount);
    RealMatrix lambdaRte = MatrixUtils.createRealMatrix(itemNum, featureCount);
    RealVector tauShp = MatrixUtils.createRealVector(new double[itemNum]);
    RealVector tauRte = MatrixUtils.createRealVector(new double[itemNum]);
    RealMatrix gammaShpNext = MatrixUtils.createRealMatrix(userNum, featureCount);
    RealMatrix lambdaShpNext = MatrixUtils.createRealMatrix(itemNum, featureCount);
    gammaShpNext = gammaShpNext.scalarAdd(a);
    lambdaShpNext = lambdaShpNext.scalarAdd(c);
    RealVector phiUI = MatrixUtils.createRealVector(new double[featureCount]);

    initialize(gammaShp, gammaRte, kappaRte, kappaShp, lambdaShp, lambdaRte, tauRte, tauShp);
    logger.info("initialization finished");

    final List<RatingMatrixEntry> train = ratings.getTrainRatings();
    final List<RatingMatrixEntry> validation = ratings.getValidationRatings();
    double avgPLLPre = Double.MAX_VALUE;
    double avgPLLCurr = 0.0;
    double diffPLL = 1.0;
    int iterCount = 1;

    while (iterCount < maxIterCount && diffPLL > threshold) {

        // update phi
        Iterator<RatingMatrixEntry> allUIPairs = train.iterator();
        while (allUIPairs.hasNext()) {
            RatingMatrixEntry entry = allUIPairs.next();
            int item = entry.getItemIndex();
            int user = entry.getUserIndex();
            double ratingUI = entry.getValue();
            if (ratingUI <= 0) {
                continue;
            }//from  ww  w  . j  a v a2  s. c  om

            for (int k = 0; k < featureCount; k++) {
                double gammaShpUK = gammaShp.getEntry(user, k);
                double gammaRteUK = gammaRte.getEntry(user, k);
                double lambdaShpIK = lambdaShp.getEntry(item, k);
                double lambdaRteIK = lambdaRte.getEntry(item, k);
                double phiUIK = Gamma.digamma(gammaShpUK) - Math.log(gammaRteUK) + Gamma.digamma(lambdaShpIK)
                        - Math.log(lambdaRteIK);
                phiUI.setEntry(k, phiUIK);
            }
            logNormalize(phiUI);

            if (ratingUI > 1) {
                phiUI.mapMultiplyToSelf(ratingUI);
            }

            for (int k = 0; k < featureCount; k++) {
                double value = phiUI.getEntry(k);
                gammaShpNext.addToEntry(user, k, value);
                lambdaShpNext.addToEntry(item, k, value);
            }

        }
        logger.info("iteration {} first phrase update finished", iterCount);

        RealVector gammaRteSecondTerm = MatrixUtils.createRealVector(new double[featureCount]);
        for (int k = 0; k < featureCount; k++) {
            double gammaRteUK = 0.0;
            for (int item = 0; item < itemNum; item++) {
                gammaRteUK += lambdaShp.getEntry(item, k) / lambdaRte.getEntry(item, k);
            }
            gammaRteSecondTerm.setEntry(k, gammaRteUK);
        }

        // update user parameters
        double kappaRteFirstTerm = aPrime / bPrime;
        for (int user = 0; user < userNum; user++) {

            double gammaRteUKFirstTerm = kappaShp.getEntry(user) / kappaRte.getEntry(user);
            double kappaRteU = 0.0;

            for (int k = 0; k < featureCount; k++) {
                double gammaShpUK = gammaShpNext.getEntry(user, k);
                gammaShp.setEntry(user, k, gammaShpUK);
                gammaShpNext.setEntry(user, k, a);
                double gammaRteUK = gammaRteSecondTerm.getEntry(k);
                gammaRteUK += gammaRteUKFirstTerm;
                gammaRte.setEntry(user, k, gammaRteUK);
                kappaRteU += gammaShpUK / gammaRteUK;
            }
            kappaRteU += kappaRteFirstTerm;
            kappaRte.setEntry(user, kappaRteU);
        }

        logger.info("iteration {} second phrase update finished", iterCount);

        RealVector lambdaRteSecondTerm = MatrixUtils.createRealVector(new double[featureCount]);
        for (int k = 0; k < featureCount; k++) {
            double lambdaRteIK = 0.0;
            for (int user = 0; user < userNum; user++) {
                lambdaRteIK += gammaShp.getEntry(user, k) / gammaRte.getEntry(user, k);
            }
            lambdaRteSecondTerm.setEntry(k, lambdaRteIK);
        }

        // update item parameters
        double tauRteFirstTerm = cPrime / dPrime;
        for (int item = 0; item < itemNum; item++) {

            double lambdaRteFirstTerm = tauShp.getEntry(item) / tauRte.getEntry(item);
            double tauRteI = 0.0;

            for (int k = 0; k < featureCount; k++) {
                double lambdaShpIK = lambdaShpNext.getEntry(item, k);
                lambdaShp.setEntry(item, k, lambdaShpIK);
                lambdaShpNext.setEntry(item, k, c);
                double lambdaRteIK = lambdaRteSecondTerm.getEntry(k);

                // plus first term
                lambdaRteIK += lambdaRteFirstTerm;
                lambdaRte.setEntry(item, k, lambdaRteIK);
                // update tauRteI second term
                tauRteI += lambdaShpIK / lambdaRteIK;
            }
            tauRteI += tauRteFirstTerm;
            tauRte.setEntry(item, tauRteI);
        }

        logger.info("iteration {} third phrase update finished", iterCount);

        // compute average predictive log likelihood of validation data per {@code iterationfrequency} iterations

        if (iterCount == 1) {
            for (int user = 0; user < userNum; user++) {
                kappaShp.setEntry(user, kappaShpU);
            }
            for (int item = 0; item < itemNum; item++) {
                tauShp.setEntry(item, tauShpI);
            }
        }

        if ((iterCount % iterationFrequency) == 0) {
            Iterator<RatingMatrixEntry> valIter = validation.iterator();
            avgPLLCurr = 0.0;

            while (valIter.hasNext()) {
                RatingMatrixEntry ratingEntry = valIter.next();
                int user = ratingEntry.getUserIndex();
                int item = ratingEntry.getItemIndex();
                double rating = ratingEntry.getValue();
                double eThetaBeta = 0.0;
                for (int k = 0; k < featureCount; k++) {
                    double eThetaUK = gammaShp.getEntry(user, k) / gammaRte.getEntry(user, k);
                    double eBetaIK = lambdaShp.getEntry(item, k) / lambdaRte.getEntry(item, k);
                    eThetaBeta += eThetaUK * eBetaIK;
                }
                double pLL = 0.0;
                if (isProbPredition) {
                    pLL = (rating == 0) ? (-eThetaBeta) : Math.log(1 - Math.exp(-eThetaBeta));
                } else {
                    pLL = rating * Math.log(eThetaBeta) - eThetaBeta - Gamma.logGamma(rating + 1);
                }
                avgPLLCurr += pLL;
            }
            avgPLLCurr = avgPLLCurr / validation.size();
            diffPLL = Math.abs((avgPLLCurr - avgPLLPre) / avgPLLPre);
            avgPLLPre = avgPLLCurr;
            logger.info("iteration {} with current average predictive log likelihood {} and the change is {}",
                    iterCount, avgPLLCurr, diffPLL);
        }
        iterCount++;
    }

    // construct feature matrix used by HPFModel
    RealMatrix eTheta = MatrixUtils.createRealMatrix(userNum, featureCount);
    RealMatrix eBeta = MatrixUtils.createRealMatrix(itemNum, featureCount);
    for (int user = 0; user < userNum; user++) {
        RealVector gammaShpU = gammaShp.getRowVector(user);
        RealVector gammaRteU = gammaRte.getRowVector(user);
        RealVector eThetaU = gammaShpU.ebeDivide(gammaRteU);
        eTheta.setRowVector(user, eThetaU);
        logger.info("Training user {} features finished", user);
    }

    for (int item = 0; item < itemNum; item++) {
        RealVector lambdaShpI = lambdaShp.getRowVector(item);
        RealVector lambdaRteI = lambdaRte.getRowVector(item);
        RealVector eBetaI = lambdaShpI.ebeDivide(lambdaRteI);
        eBeta.setRowVector(item, eBetaI);
        logger.info("Training item {} features finished", item);
    }

    KeyIndex uidx = ratings.getUserIndex();
    KeyIndex iidx = ratings.getItemIndex();

    return new HPFModel(eTheta, eBeta, uidx, iidx);
}

From source file:org.lenskit.pf.HPFModelProvider.java

/**
 * Initialization of parameter matrices//from www .  j  a  v a2s .c om
 * @param gammaShp
 * @param gammaRte
 * @param kappaRte
 * @param kappaShp
 * @param lambdaShp
 * @param lambdaRte
 * @param tauRte
 * @param tauShp
 */
public void initialize(RealMatrix gammaShp, RealMatrix gammaRte, RealVector kappaRte, RealVector kappaShp,
        RealMatrix lambdaShp, RealMatrix lambdaRte, RealVector tauRte, RealVector tauShp) {
    final int userNum = ratings.getUserIndex().size();
    final int itemNum = ratings.getItemIndex().size();
    final int featureCount = hyperParameters.getFeatureCount();
    final double a = hyperParameters.getUserWeightShpPrior();
    final double aPrime = hyperParameters.getUserActivityShpPrior();
    final double bPrime = hyperParameters.getUserActivityPriorMean();
    final double c = hyperParameters.getItemWeightShpPrior();
    final double cPrime = hyperParameters.getItemActivityShpPrior();
    final double dPrime = hyperParameters.getItemActivityPriorMean();
    // Initialization
    Random random = new Random(rndSeed);
    final double kRte = aPrime + featureCount;
    final double tRte = cPrime + featureCount;

    for (int u = 0; u < userNum; u++) {
        for (int k = 0; k < featureCount; k++) {
            double valueShp = a + maxOffsetShp * random.nextDouble();
            double valueRte = aPrime + maxOffsetRte * random.nextDouble();
            gammaShp.setEntry(u, k, valueShp);
            gammaRte.setEntry(u, k, valueRte);
        }

        double kShp = aPrime + maxOffsetShp * random.nextDouble();
        kappaRte.setEntry(u, kRte);
        kappaShp.setEntry(u, kShp);
    }

    for (int i = 0; i < itemNum; i++) {
        for (int k = 0; k < featureCount; k++) {
            double valueShp = c + maxOffsetShp * random.nextDouble();
            double valueRte = cPrime + maxOffsetRte * random.nextDouble();
            lambdaShp.setEntry(i, k, valueShp);
            lambdaRte.setEntry(i, k, valueRte);
        }
        double tShp = cPrime + maxOffsetShp * random.nextDouble();
        tauRte.setEntry(i, tRte);
        tauShp.setEntry(i, tShp);
    }

}

From source file:org.nd4j.linalg.Nd4jTestsComparisonFortran.java

@Test
public void testGemvApacheCommons() {

    int[] rowsArr = new int[] { 4, 4, 4, 8, 8, 8 };
    int[] colsArr = new int[] { 2, 1, 10, 2, 1, 10 };

    for (int x = 0; x < rowsArr.length; x++) {
        int rows = rowsArr[x];
        int cols = colsArr[x];

        List<Pair<INDArray, String>> matrices = NDArrayCreationUtil.getAllTestMatricesWithShape(rows, cols,
                12345);//w w w .j a v  a 2  s. co m
        List<Pair<INDArray, String>> vectors = NDArrayCreationUtil.getAllTestMatricesWithShape(cols, 1, 12345);

        for (int i = 0; i < matrices.size(); i++) {
            for (int j = 0; j < vectors.size(); j++) {

                Pair<INDArray, String> p1 = matrices.get(i);
                Pair<INDArray, String> p2 = vectors.get(j);
                String errorMsg = getTestWithOpsErrorMsg(i, j, "mmul", p1, p2);

                INDArray m = p1.getFirst();
                INDArray v = p2.getFirst();

                RealMatrix rm = new BlockRealMatrix(m.rows(), m.columns());
                for (int r = 0; r < m.rows(); r++) {
                    for (int c = 0; c < m.columns(); c++) {
                        double d = m.getDouble(r, c);
                        rm.setEntry(r, c, d);
                    }
                }

                RealMatrix rv = new BlockRealMatrix(cols, 1);
                for (int r = 0; r < v.rows(); r++) {
                    double d = v.getDouble(r, 0);
                    rv.setEntry(r, 0, d);
                }

                INDArray gemv = m.mmul(v);
                RealMatrix gemv2 = rm.multiply(rv);

                assertArrayEquals(new int[] { rows, 1 }, gemv.shape());
                assertArrayEquals(new int[] { rows, 1 },
                        new int[] { gemv2.getRowDimension(), gemv2.getColumnDimension() });

                //Check entries:
                for (int r = 0; r < rows; r++) {
                    double exp = gemv2.getEntry(r, 0);
                    double act = gemv.getDouble(r, 0);
                    assertEquals(errorMsg, exp, act, 1e-5);
                }
            }
        }
    }
}

From source file:org.opentestsystem.airose.linear.Matrices.java

public static void copyTo(Matrix matrix, Matrix output) {
    RealMatrix source = matrix._matrix;//from   w ww.  j  ava  2s  .  c o  m
    RealMatrix destination = output._matrix;
    for (int row = 0; row < source.getRowDimension(); ++row) {
        for (int column = 0; column < source.getColumnDimension(); ++column) {
            destination.setEntry(row, column, source.getEntry(row, column));
        }
    }
}

From source file:org.orekit.frames.TransformTest.java

@Test
public void testLinear() {

    RandomGenerator random = new Well19937a(0x14f6411217b148d8l);
    for (int n = 0; n < 100; ++n) {
        Transform t = randomTransform(random);

        // build an equivalent linear transform by extracting raw translation/rotation
        RealMatrix linearA = MatrixUtils.createRealMatrix(3, 4);
        linearA.setSubMatrix(t.getRotation().getMatrix(), 0, 0);
        Vector3D rt = t.getRotation().applyTo(t.getTranslation());
        linearA.setEntry(0, 3, rt.getX());
        linearA.setEntry(1, 3, rt.getY());
        linearA.setEntry(2, 3, rt.getZ());

        // build an equivalent linear transform by observing transformed points
        RealMatrix linearB = MatrixUtils.createRealMatrix(3, 4);
        Vector3D p0 = t.transformPosition(Vector3D.ZERO);
        Vector3D pI = t.transformPosition(Vector3D.PLUS_I).subtract(p0);
        Vector3D pJ = t.transformPosition(Vector3D.PLUS_J).subtract(p0);
        Vector3D pK = t.transformPosition(Vector3D.PLUS_K).subtract(p0);
        linearB.setColumn(0, new double[] { pI.getX(), pI.getY(), pI.getZ() });
        linearB.setColumn(1, new double[] { pJ.getX(), pJ.getY(), pJ.getZ() });
        linearB.setColumn(2, new double[] { pK.getX(), pK.getY(), pK.getZ() });
        linearB.setColumn(3, new double[] { p0.getX(), p0.getY(), p0.getZ() });

        // both linear transforms should be equal
        Assert.assertEquals(0.0, linearB.subtract(linearA).getNorm(), 1.0e-15 * linearA.getNorm());

        for (int i = 0; i < 100; ++i) {
            Vector3D p = randomVector(1.0e3, random);
            Vector3D q = t.transformPosition(p);

            double[] qA = linearA.operate(new double[] { p.getX(), p.getY(), p.getZ(), 1.0 });
            Assert.assertEquals(q.getX(), qA[0], 1.0e-13 * p.getNorm());
            Assert.assertEquals(q.getY(), qA[1], 1.0e-13 * p.getNorm());
            Assert.assertEquals(q.getZ(), qA[2], 1.0e-13 * p.getNorm());

            double[] qB = linearB.operate(new double[] { p.getX(), p.getY(), p.getZ(), 1.0 });
            Assert.assertEquals(q.getX(), qB[0], 1.0e-10 * p.getNorm());
            Assert.assertEquals(q.getY(), qB[1], 1.0e-10 * p.getNorm());
            Assert.assertEquals(q.getZ(), qB[2], 1.0e-10 * p.getNorm());

        }//from  ww w. j av a 2s.c om

    }

}

From source file:org.orekit.utils.AngularCoordinates.java

/** Find a vector from two known cross products.
 * <p>//from w  ww  . j av  a2  s .c  o  m
 * We want to find  such that:   v? = c? and   v = c
 * </p>
 * <p>
 * The first equation (  v? = c?) will always be fulfilled exactly,
 * and the second one will be fulfilled if possible.
 * </p>
 * @param v1 vector forming the first known cross product
 * @param c1 know vector for cross product   v?
 * @param v2 vector forming the second known cross product
 * @param c2 know vector for cross product   v
 * @param tolerance relative tolerance factor used to check singularities
 * @return vector  such that:   v? = c? and   v = c
 * @exception MathIllegalArgumentException if vectors are inconsistent and
 * no solution can be found
 */
private static Vector3D inverseCrossProducts(final Vector3D v1, final Vector3D c1, final Vector3D v2,
        final Vector3D c2, final double tolerance) throws MathIllegalArgumentException {

    final double v12 = v1.getNormSq();
    final double v1n = FastMath.sqrt(v12);
    final double v22 = v2.getNormSq();
    final double v2n = FastMath.sqrt(v22);
    final double threshold = tolerance * FastMath.max(v1n, v2n);

    Vector3D omega;

    try {
        // create the over-determined linear system representing the two cross products
        final RealMatrix m = MatrixUtils.createRealMatrix(6, 3);
        m.setEntry(0, 1, v1.getZ());
        m.setEntry(0, 2, -v1.getY());
        m.setEntry(1, 0, -v1.getZ());
        m.setEntry(1, 2, v1.getX());
        m.setEntry(2, 0, v1.getY());
        m.setEntry(2, 1, -v1.getX());
        m.setEntry(3, 1, v2.getZ());
        m.setEntry(3, 2, -v2.getY());
        m.setEntry(4, 0, -v2.getZ());
        m.setEntry(4, 2, v2.getX());
        m.setEntry(5, 0, v2.getY());
        m.setEntry(5, 1, -v2.getX());

        final RealVector rhs = MatrixUtils.createRealVector(
                new double[] { c1.getX(), c1.getY(), c1.getZ(), c2.getX(), c2.getY(), c2.getZ() });

        // find the best solution we can
        final DecompositionSolver solver = new QRDecomposition(m, threshold).getSolver();
        final RealVector v = solver.solve(rhs);
        omega = new Vector3D(v.getEntry(0), v.getEntry(1), v.getEntry(2));

    } catch (SingularMatrixException sme) {

        // handle some special cases for which we can compute a solution
        final double c12 = c1.getNormSq();
        final double c1n = FastMath.sqrt(c12);
        final double c22 = c2.getNormSq();
        final double c2n = FastMath.sqrt(c22);

        if (c1n <= threshold && c2n <= threshold) {
            // simple special case, velocities are cancelled
            return Vector3D.ZERO;
        } else if (v1n <= threshold && c1n >= threshold) {
            // this is inconsistent, if v? is zero, c? must be 0 too
            throw new NumberIsTooLargeException(c1n, 0, true);
        } else if (v2n <= threshold && c2n >= threshold) {
            // this is inconsistent, if v is zero, c must be 0 too
            throw new NumberIsTooLargeException(c2n, 0, true);
        } else if (Vector3D.crossProduct(v1, v2).getNorm() <= threshold && v12 > threshold) {
            // simple special case, v is redundant with v?, we just ignore it
            // use the simplest : orthogonal to both v? and c?
            omega = new Vector3D(1.0 / v12, Vector3D.crossProduct(v1, c1));
        } else {
            throw sme;
        }

    }

    // check results
    final double d1 = Vector3D.distance(Vector3D.crossProduct(omega, v1), c1);
    if (d1 > threshold) {
        throw new NumberIsTooLargeException(d1, 0, true);
    }

    final double d2 = Vector3D.distance(Vector3D.crossProduct(omega, v2), c2);
    if (d2 > threshold) {
        throw new NumberIsTooLargeException(d2, 0, true);
    }

    return omega;

}

From source file:org.rhwlab.BHC.Testing.java

static public void main(String[] args) {
    String[] tokens = "0.011332651026552858 3.41268617023919E-4 0.0018087352262063756 3.4126861702391887E-4 0.013068389158168082 -0.0018712410627799538 0.001808735226206376 -0.0018712410627799538 0.012536567307833844"
            .split(" ");

    RealMatrix m = new Array2DRowRealMatrix(3, 3);
    for (int r = 0; r < 3; ++r) {
        for (int c = 0; c < 3; ++c) {
            m.setEntry(r, c, Double.valueOf(tokens[3 * r + c]));
        }/*from w  w w  .j  a  v  a2  s.  c  o  m*/
    }
    LUDecomposition lud = new LUDecomposition(m);
    RealMatrix mInv = lud.getSolver().getInverse();
    EigenDecomposition decomp = new EigenDecomposition(lud.getSolver().getInverse());
    double[] e = decomp.getRealEigenvalues();
    int thsdfui = 0;
}

From source file:org.rhwlab.dispim.nucleus.NamedNucleusFile.java

License:asdf

static public RealMatrix rotationMatrix(Vector3D A, Vector3D B) {
    Vector3D a = A.normalize();//from w  ww .  j av a 2 s . c  om
    Vector3D b = B.normalize();
    Vector3D v = a.crossProduct(b);

    double s = v.getNormSq();
    double c = a.dotProduct(b);

    RealMatrix vx = MatrixUtils.createRealMatrix(3, 3);
    vx.setEntry(1, 0, v.getZ());
    vx.setEntry(0, 1, -v.getZ());
    vx.setEntry(2, 0, -v.getY());
    vx.setEntry(0, 2, v.getY());
    vx.setEntry(2, 1, v.getX());
    vx.setEntry(1, 2, -v.getX());

    RealMatrix vx2 = vx.multiply(vx);
    RealMatrix scaled = vx2.scalarMultiply((1.0 - c) / s);

    RealMatrix ident = MatrixUtils.createRealIdentityMatrix(3);
    RealMatrix sum = vx.add(scaled);
    RealMatrix ret = ident.add(sum);

    return ret;
}

From source file:org.rhwlab.dispim.nucleus.Nucleus.java

private RealMatrix reverseHandedness(RealMatrix m) {
    RealMatrix ret = m.copy();
    for (int c = 0; c < m.getColumnDimension(); ++c) {

        ret.setEntry(0, c, -m.getEntry(0, c));
    }/*w w  w. j  ava 2s .  co  m*/
    return ret;
}