List of usage examples for org.apache.mahout.math Matrix plus
Matrix plus(Matrix x);
From source file:org.qcri.pca.SPCADriver.java
/** * Run PPCA sequentially given the small input Y which fit into memory This * could be used also on sampled data from a distributed matrix * //from w w w. j a v a2s . c o m * Note: this implementation ignore NaN values by replacing them with 0 * * @param conf * the configuration * @param centralY * the input matrix * @param initVal * the initial values for C and ss * @param MAX_ROUNDS * maximum number of iterations * @return the error * @throws Exception */ double runSequential_JacobVersion(Configuration conf, Matrix centralY, InitialValues initVal, final int MAX_ROUNDS) { Matrix centralC = initVal.C;// the current implementation doesn't use initial ss of // initVal final int nRows = centralY.numRows(); final int nCols = centralY.numCols(); final int nPCs = centralC.numCols(); final float threshold = 0.00001f; log.info("tracec= " + PCACommon.trace(centralC)); // Y = Y - mean(Ye) // Also normalize the matrix for (int r = 0; r < nRows; r++) for (int c = 0; c < nCols; c++) if (new Double(centralY.getQuick(r, c)).isNaN()) { centralY.setQuick(r, c, 0); } Vector mean = centralY.aggregateColumns(new VectorFunction() { @Override public double apply(Vector v) { return v.zSum() / nRows; } }); Vector spanVector = new DenseVector(nCols); for (int c = 0; c < nCols; c++) { Vector col = centralY.viewColumn(c); double max = col.maxValue(); double min = col.minValue(); double span = max - min; spanVector.setQuick(c, span); } for (int r = 0; r < nRows; r++) for (int c = 0; c < nCols; c++) centralY.set(r, c, (centralY.get(r, c) - mean.get(c)) / (spanVector.getQuick(c) != 0 ? spanVector.getQuick(c) : 1)); // -------------------------- initialization // CtC = C'*C; Matrix centralCtC = centralC.transpose().times(centralC); log.info("tracectc= " + PCACommon.trace(centralCtC)); log.info("traceinvctc= " + PCACommon.trace(inv(centralCtC))); log.info("traceye= " + PCACommon.trace(centralY)); // X = Ye * C * inv(CtC); Matrix centralX = centralY.times(centralC).times(inv(centralCtC)); log.info("tracex= " + PCACommon.trace(centralX)); // recon = X * C'; Matrix recon = centralX.times(centralC.transpose()); log.info("tracerec= " + PCACommon.trace(recon)); // ss = sum(sum((recon-Ye).^2)) / (N*D-missing); double ss = recon.minus(centralY).assign(new DoubleFunction() { @Override public double apply(double arg1) { return arg1 * arg1; } }).zSum() / (nRows * nCols); log.info("SSSSSSSSSSSSSSSSSSSSSSSSSSSS " + ss); int count = 1; // old = Inf; double old = Double.MAX_VALUE; // -------------------------- EM Iterations // while count int round = 0; while (round < MAX_ROUNDS && count > 0) { round++; // ------------------ E-step, (co)variances // Sx = inv( eye(d) + CtC/ss ); Matrix centralSx = eye(nPCs).plus(centralCtC.divide(ss)); centralSx = inv(centralSx); // ------------------ E-step expected value // X = Ye*C*(Sx/ss); centralX = centralY.times(centralC).times(centralSx.divide(ss)); // ------------------ M-step // SumXtX = X'*X; Matrix centralSumXtX = centralX.transpose().times(centralX); // C = (Ye'*X) / (SumXtX + N*Sx ); Matrix tmpInv = inv(centralSumXtX.plus(centralSx.times(nRows))); centralC = centralY.transpose().times(centralX).times(tmpInv); // CtC = C'*C; centralCtC = centralC.transpose().times(centralC); // ss = ( sum(sum( (X*C'-Ye).^2 )) + N*sum(sum(CtC.*Sx)) + // missing*ss_old ) /(N*D); recon = centralX.times(centralC.transpose()); double error = recon.minus(centralY).assign(new DoubleFunction() { @Override public double apply(double arg1) { return arg1 * arg1; } }).zSum(); ss = error + nRows * dot(centralCtC.clone(), centralSx).zSum(); ss /= (nRows * nCols); log.info("SSSSSSSSSSSSSSSSSSSSSSSSSSSS " + ss); double traceSx = PCACommon.trace(centralSx); double traceX = PCACommon.trace(centralX); double traceSumXtX = PCACommon.trace(centralSumXtX); double traceC = PCACommon.trace(centralC); double traceCtC = PCACommon.trace(centralCtC); log.info("TTTTTTTTTTTTTTTTT " + traceSx + " " + traceX + " " + traceSumXtX + " " + traceC + " " + traceCtC + " " + 0); // objective = N*D + N*(D*log(ss) +PCACommon.trace(Sx)-log(det(Sx)) ) // +PCACommon.trace(SumXtX) -missing*log(ss_old); double objective = nRows * nCols + nRows * (nCols * Math.log(ss) + PCACommon.trace(centralSx) - Math.log(centralSx.determinant())) + PCACommon.trace(centralSumXtX); double rel_ch = Math.abs(1 - objective / old); old = objective; count++; if (rel_ch < threshold && count > 5) count = 0; System.out.printf("Objective: %.6f relative change: %.6f \n", objective, rel_ch); } double norm1Y = centralY.aggregateColumns(new VectorNorm1()).maxValue(); log.info("Norm1 of Y is: " + norm1Y); Matrix newYerror = centralY.minus(centralX.times(centralC.transpose())); double norm1Err = newYerror.aggregateColumns(new VectorNorm1()).maxValue(); log.info("Norm1 of the reconstruction error is: " + norm1Err); initVal.C = centralC; initVal.ss = ss; return norm1Err / norm1Y; }
From source file:org.trustedanalytics.atk.giraph.algorithms.als.AlternatingLeastSquaresComputation.java
License:Apache License
@Override public void compute(Vertex<CFVertexId, VertexData4CFWritable, EdgeData4CFWritable> vertex, Iterable<MessageData4CFWritable> messages) throws IOException { long step = getSuperstep(); if (step == 0) { initialize(vertex);/*from w w w . j a v a 2s .co m*/ vertex.voteToHalt(); return; } Vector currentValue = vertex.getValue().getVector(); double currentBias = vertex.getValue().getBias(); // update aggregators every (2 * interval) super steps if ((step % (2 * learningCurveOutputInterval)) == 0) { double errorOnTrain = 0d; double errorOnValidate = 0d; double errorOnTest = 0d; int numTrain = 0; for (MessageData4CFWritable message : messages) { EdgeType et = message.getType(); double weight = message.getWeight(); Vector vector = message.getVector(); double otherBias = message.getBias(); double predict = currentBias + otherBias + currentValue.dot(vector); double e = weight - predict; switch (et) { case TRAIN: errorOnTrain += e * e; numTrain++; break; case VALIDATE: errorOnValidate += e * e; break; case TEST: errorOnTest += e * e; break; default: throw new IllegalArgumentException("Unknown recognized edge type: " + et.toString()); } } double costOnTrain = 0d; if (numTrain > 0) { costOnTrain = errorOnTrain / numTrain + lambda * (currentBias * currentBias + currentValue.dot(currentValue)); } aggregate(SUM_TRAIN_COST, new DoubleWritable(costOnTrain)); aggregate(SUM_VALIDATE_ERROR, new DoubleWritable(errorOnValidate)); aggregate(SUM_TEST_ERROR, new DoubleWritable(errorOnTest)); } // update vertex value if (step < maxSupersteps) { // xxt records the result of x times x transpose Matrix xxt = new DenseMatrix(featureDimension, featureDimension); xxt = xxt.assign(0d); // xr records the result of x times rating Vector xr = currentValue.clone().assign(0d); int numTrain = 0; for (MessageData4CFWritable message : messages) { EdgeType et = message.getType(); if (et == EdgeType.TRAIN) { double weight = message.getWeight(); Vector vector = message.getVector(); double otherBias = message.getBias(); xxt = xxt.plus(vector.cross(vector)); xr = xr.plus(vector.times(weight - currentBias - otherBias)); numTrain++; } } xxt = xxt.plus(new DiagonalMatrix(lambda * numTrain, featureDimension)); Matrix bMatrix = new DenseMatrix(featureDimension, 1).assignColumn(0, xr); Vector value = new QRDecomposition(xxt).solve(bMatrix).viewColumn(0); vertex.getValue().setVector(value); // update vertex bias if (biasOn) { double bias = computeBias(value, messages); vertex.getValue().setBias(bias); } // send out messages for (Edge<CFVertexId, EdgeData4CFWritable> edge : vertex.getEdges()) { MessageData4CFWritable newMessage = new MessageData4CFWritable(vertex.getValue(), edge.getValue()); sendMessage(edge.getTargetVertexId(), newMessage); } } vertex.voteToHalt(); }