Examples with PointValuePair org.apache.commons.math3.optim.PointValuePair used on opensource projects

Example 11 with PointValuePair

use of org.apache.commons.math3.optim.PointValuePair in project GDSC-SMLM by aherbert.

the class MaximumLikelihoodFitter method computeFit.

/*
	 * (non-Javadoc)
	 * 
	 * @see gdsc.smlm.fitting.nonlinear.BaseFunctionSolver#computeFit(double[], double[], double[], double[])
	 */
public FitStatus computeFit(double[] y, double[] y_fit, double[] a, double[] a_dev) {
    final int n = y.length;
    LikelihoodWrapper maximumLikelihoodFunction = createLikelihoodWrapper((NonLinearFunction) f, n, y, a);
    @SuppressWarnings("rawtypes") BaseOptimizer baseOptimiser = null;
    try {
        double[] startPoint = getInitialSolution(a);
        PointValuePair optimum = null;
        if (searchMethod == SearchMethod.POWELL || searchMethod == SearchMethod.POWELL_BOUNDED || searchMethod == SearchMethod.POWELL_ADAPTER) {
            // Non-differentiable version using Powell Optimiser
            // This is as per the method in Numerical Recipes 10.5 (Direction Set (Powell's) method)
            // I could extend the optimiser and implement bounds on the directions moved. However the mapping
            // adapter seems to work OK.
            final boolean basisConvergence = false;
            // Perhaps these thresholds should be tighter?
            // The default is to use the sqrt() of the overall tolerance
            //final double lineRel = FastMath.sqrt(relativeThreshold);
            //final double lineAbs = FastMath.sqrt(absoluteThreshold);
            //final double lineRel = relativeThreshold * 1e2;
            //final double lineAbs = absoluteThreshold * 1e2;
            // Since we are fitting only a small number of parameters then just use the same tolerance 
            // for each search direction
            final double lineRel = relativeThreshold;
            final double lineAbs = absoluteThreshold;
            CustomPowellOptimizer o = new CustomPowellOptimizer(relativeThreshold, absoluteThreshold, lineRel, lineAbs, null, basisConvergence);
            baseOptimiser = o;
            OptimizationData maxIterationData = null;
            if (getMaxIterations() > 0)
                maxIterationData = new MaxIter(getMaxIterations());
            if (searchMethod == SearchMethod.POWELL_ADAPTER) {
                // Try using the mapping adapter for a bounded Powell search
                MultivariateFunctionMappingAdapter adapter = new MultivariateFunctionMappingAdapter(new MultivariateLikelihood(maximumLikelihoodFunction), lower, upper);
                optimum = o.optimize(maxIterationData, new MaxEval(getMaxEvaluations()), new ObjectiveFunction(adapter), GoalType.MINIMIZE, new InitialGuess(adapter.boundedToUnbounded(startPoint)));
                double[] solution = adapter.unboundedToBounded(optimum.getPointRef());
                optimum = new PointValuePair(solution, optimum.getValue());
            } else {
                if (powellFunction == null) {
                    // Python code by using the sqrt of the number of photons and background.
                    if (mapGaussian) {
                        Gaussian2DFunction gf = (Gaussian2DFunction) f;
                        // Re-map signal and background using the sqrt
                        int[] indices = gf.gradientIndices();
                        int[] map = new int[indices.length];
                        int count = 0;
                        // Background is always first
                        if (indices[0] == Gaussian2DFunction.BACKGROUND) {
                            map[count++] = 0;
                        }
                        // Look for the Signal in multiple peak 2D Gaussians
                        for (int i = 1; i < indices.length; i++) if (indices[i] % 6 == Gaussian2DFunction.SIGNAL) {
                            map[count++] = i;
                        }
                        if (count > 0) {
                            powellFunction = new MappedMultivariateLikelihood(maximumLikelihoodFunction, Arrays.copyOf(map, count));
                        }
                    }
                    if (powellFunction == null) {
                        powellFunction = new MultivariateLikelihood(maximumLikelihoodFunction);
                    }
                }
                // Update the maximum likelihood function in the Powell function wrapper
                powellFunction.fun = maximumLikelihoodFunction;
                OptimizationData positionChecker = null;
                // new org.apache.commons.math3.optim.PositionChecker(relativeThreshold, absoluteThreshold);
                SimpleBounds simpleBounds = null;
                if (powellFunction.isMapped()) {
                    MappedMultivariateLikelihood adapter = (MappedMultivariateLikelihood) powellFunction;
                    if (searchMethod == SearchMethod.POWELL_BOUNDED)
                        simpleBounds = new SimpleBounds(adapter.map(lower), adapter.map(upper));
                    optimum = o.optimize(maxIterationData, new MaxEval(getMaxEvaluations()), new ObjectiveFunction(powellFunction), GoalType.MINIMIZE, new InitialGuess(adapter.map(startPoint)), positionChecker, simpleBounds);
                    double[] solution = adapter.unmap(optimum.getPointRef());
                    optimum = new PointValuePair(solution, optimum.getValue());
                } else {
                    if (searchMethod == SearchMethod.POWELL_BOUNDED)
                        simpleBounds = new SimpleBounds(lower, upper);
                    optimum = o.optimize(maxIterationData, new MaxEval(getMaxEvaluations()), new ObjectiveFunction(powellFunction), GoalType.MINIMIZE, new InitialGuess(startPoint), positionChecker, simpleBounds);
                }
            }
        } else if (searchMethod == SearchMethod.BOBYQA) {
            // Differentiable approximation using Powell's BOBYQA algorithm.
            // This is slower than the Powell optimiser and requires a high number of evaluations.
            int numberOfInterpolationPoints = this.getNumberOfFittedParameters() + 2;
            BOBYQAOptimizer o = new BOBYQAOptimizer(numberOfInterpolationPoints);
            baseOptimiser = o;
            optimum = o.optimize(new MaxEval(getMaxEvaluations()), new ObjectiveFunction(new MultivariateLikelihood(maximumLikelihoodFunction)), GoalType.MINIMIZE, new InitialGuess(startPoint), new SimpleBounds(lower, upper));
        } else if (searchMethod == SearchMethod.CMAES) {
            // TODO - Understand why the CMAES optimiser does not fit very well on test data. It appears 
            // to converge too early and the likelihood scores are not as low as the other optimisers.
            // CMAESOptimiser based on Matlab code:
            // https://www.lri.fr/~hansen/cmaes.m
            // Take the defaults from the Matlab documentation
            //Double.NEGATIVE_INFINITY;
            double stopFitness = 0;
            boolean isActiveCMA = true;
            int diagonalOnly = 0;
            int checkFeasableCount = 1;
            RandomGenerator random = new Well19937c();
            boolean generateStatistics = false;
            // The sigma determines the search range for the variables. It should be 1/3 of the initial search region.
            double[] sigma = new double[lower.length];
            for (int i = 0; i < sigma.length; i++) sigma[i] = (upper[i] - lower[i]) / 3;
            int popSize = (int) (4 + Math.floor(3 * Math.log(sigma.length)));
            // The CMAES optimiser is random and restarting can overcome problems with quick convergence.
            // The Apache commons documentations states that convergence should occur between 30N and 300N^2
            // function evaluations
            final int n30 = FastMath.min(sigma.length * sigma.length * 30, getMaxEvaluations() / 2);
            evaluations = 0;
            OptimizationData[] data = new OptimizationData[] { new InitialGuess(startPoint), new CMAESOptimizer.PopulationSize(popSize), new MaxEval(getMaxEvaluations()), new CMAESOptimizer.Sigma(sigma), new ObjectiveFunction(new MultivariateLikelihood(maximumLikelihoodFunction)), GoalType.MINIMIZE, new SimpleBounds(lower, upper) };
            // Iterate to prevent early convergence
            int repeat = 0;
            while (evaluations < n30) {
                if (repeat++ > 1) {
                    // Update the start point and population size
                    data[0] = new InitialGuess(optimum.getPointRef());
                    popSize *= 2;
                    data[1] = new CMAESOptimizer.PopulationSize(popSize);
                }
                CMAESOptimizer o = new CMAESOptimizer(getMaxIterations(), stopFitness, isActiveCMA, diagonalOnly, checkFeasableCount, random, generateStatistics, new SimpleValueChecker(relativeThreshold, absoluteThreshold));
                baseOptimiser = o;
                PointValuePair result = o.optimize(data);
                iterations += o.getIterations();
                evaluations += o.getEvaluations();
                //		o.getEvaluations(), totalEvaluations);
                if (optimum == null || result.getValue() < optimum.getValue()) {
                    optimum = result;
                }
            }
            // Prevent incrementing the iterations again
            baseOptimiser = null;
        } else if (searchMethod == SearchMethod.BFGS) {
            // BFGS can use an approximate line search minimisation where as Powell and conjugate gradient
            // methods require a more accurate line minimisation. The BFGS search does not do a full 
            // minimisation but takes appropriate steps in the direction of the current gradient.
            // Do not use the convergence checker on the value of the function. Use the convergence on the 
            // point coordinate and gradient
            //BFGSOptimizer o = new BFGSOptimizer(new SimpleValueChecker(rel, abs));
            BFGSOptimizer o = new BFGSOptimizer();
            baseOptimiser = o;
            // Configure maximum step length for each dimension using the bounds
            double[] stepLength = new double[lower.length];
            for (int i = 0; i < stepLength.length; i++) {
                stepLength[i] = (upper[i] - lower[i]) * 0.3333333;
                if (stepLength[i] <= 0)
                    stepLength[i] = Double.POSITIVE_INFINITY;
            }
            // The GoalType is always minimise so no need to pass this in
            OptimizationData positionChecker = null;
            //new org.apache.commons.math3.optim.PositionChecker(relativeThreshold, absoluteThreshold);
            optimum = o.optimize(new MaxEval(getMaxEvaluations()), new ObjectiveFunctionGradient(new MultivariateVectorLikelihood(maximumLikelihoodFunction)), new ObjectiveFunction(new MultivariateLikelihood(maximumLikelihoodFunction)), new InitialGuess(startPoint), new SimpleBounds(lowerConstraint, upperConstraint), new BFGSOptimizer.GradientTolerance(relativeThreshold), positionChecker, new BFGSOptimizer.StepLength(stepLength));
        } else {
            // The line search algorithm often fails. This is due to searching into a region where the 
            // function evaluates to a negative so has been clipped. This means the upper bound of the line
            // cannot be found.
            // Note that running it on an easy problem (200 photons with fixed fitting (no background)) the algorithm
            // does sometimes produces results better than the Powell algorithm but it is slower.
            BoundedNonLinearConjugateGradientOptimizer o = new BoundedNonLinearConjugateGradientOptimizer((searchMethod == SearchMethod.CONJUGATE_GRADIENT_FR) ? Formula.FLETCHER_REEVES : Formula.POLAK_RIBIERE, new SimpleValueChecker(relativeThreshold, absoluteThreshold));
            baseOptimiser = o;
            // Note: The gradients may become unstable at the edge of the bounds. Or they will not change 
            // direction if the true solution is on the bounds since the gradient will always continue 
            // towards the bounds. This is key to the conjugate gradient method. It searches along a vector 
            // until the direction of the gradient is in the opposite direction (using dot products, i.e. 
            // cosine of angle between them)
            // NR 10.7 states there is no advantage of the variable metric DFP or BFGS methods over
            // conjugate gradient methods. So I will try these first.
            // Try this:
            // Adapt the conjugate gradient optimiser to use the gradient to pick the search direction
            // and then for the line minimisation. However if the function is out of bounds then clip the 
            // variables at the bounds and continue. 
            // If the current point is at the bounds and the gradient is to continue out of bounds then 
            // clip the gradient too.
            // Or: just use the gradient for the search direction then use the line minimisation/rest
            // as per the Powell optimiser. The bounds should limit the search.
            // I tried a Bounded conjugate gradient optimiser with clipped variables:
            // This sometimes works. However when the variables go a long way out of the expected range the gradients
            // can have vastly different magnitudes. This results in the algorithm stalling since the gradients
            // can be close to zero and the some of the parameters are no longer adjusted.
            // Perhaps this can be looked for and the algorithm then gives up and resorts to a Powell optimiser from 
            // the current point.
            // Changed the bracketing step to very small (default is 1, changed to 0.001). This improves the 
            // performance. The gradient direction is very sensitive to small changes in the coordinates so a 
            // tighter bracketing of the line search helps.
            // Tried using a non-gradient method for the line search copied from the Powell optimiser:
            // This also works when the bracketing step is small but the number of iterations is higher.
            // 24.10.2014: I have tried to get conjugate gradient to work but the gradient function 
            // must not behave suitably for the optimiser. In the current state both methods of using a 
            // Bounded Conjugate Gradient Optimiser perform poorly relative to other optimisers:
            // Simulated : n=1000, signal=200, x=0.53, y=0.47
            // LVM : n=1000, signal=171, x=0.537, y=0.471 (1.003s)
            // Powell : n=1000, signal=187, x=0.537, y=0.48 (1.238s)
            // Gradient based PR (constrained): n=858, signal=161, x=0.533, y=0.474 (2.54s)
            // Gradient based PR (bounded): n=948, signal=161, x=0.533, y=0.473 (2.67s)
            // Non-gradient based : n=1000, signal=151.47, x=0.535, y=0.474 (1.626s)
            // The conjugate optimisers are slower, under predict the signal by the most and in the case of 
            // the gradient based optimiser, fail to converge on some problems. This is worse when constrained
            // fitting is used and not tightly bounded fitting.
            // I will leave the code in as an option but would not recommend using it. I may remove it in the 
            // future.
            // Note: It is strange that the non-gradient based line minimisation is more successful.
            // It may be that the gradient function is not accurate (due to round off error) or that it is
            // simply wrong when far from the optimum. My JUnit tests only evaluate the function within the 
            // expected range of the answer.
            // Note the default step size on the Powell optimiser is 1 but the initial directions are unit vectors.
            // So our bracketing step should be a minimum of 1 / average length of the first gradient vector to prevent
            // the first step being too large when bracketing.
            final double[] gradient = new double[startPoint.length];
            maximumLikelihoodFunction.likelihood(startPoint, gradient);
            double l = 0;
            for (double d : gradient) l += d * d;
            final double bracketingStep = FastMath.min(0.001, ((l > 1) ? 1.0 / l : 1));
            //System.out.printf("Bracketing step = %f (length=%f)\n", bracketingStep, l);
            o.setUseGradientLineSearch(gradientLineMinimisation);
            optimum = o.optimize(new MaxEval(getMaxEvaluations()), new ObjectiveFunctionGradient(new MultivariateVectorLikelihood(maximumLikelihoodFunction)), new ObjectiveFunction(new MultivariateLikelihood(maximumLikelihoodFunction)), GoalType.MINIMIZE, new InitialGuess(startPoint), new SimpleBounds(lowerConstraint, upperConstraint), new BoundedNonLinearConjugateGradientOptimizer.BracketingStep(bracketingStep));
        //maximumLikelihoodFunction.value(solution, gradient);
        //System.out.printf("Iter = %d, %g @ %s : %s\n", iterations, ll, Arrays.toString(solution),
        //		Arrays.toString(gradient));
        }
        final double[] solution = optimum.getPointRef();
        setSolution(a, solution);
        if (a_dev != null) {
            // Assume the Maximum Likelihood estimator returns the optimum fit (achieves the Cramer Roa
            // lower bounds) and so the covariance can be obtained from the Fisher Information Matrix.
            FisherInformationMatrix m = new FisherInformationMatrix(maximumLikelihoodFunction.fisherInformation(a));
            setDeviations(a_dev, m.crlb(true));
        }
        // Reverse negative log likelihood for maximum likelihood score
        value = -optimum.getValue();
    } catch (TooManyIterationsException e) {
        //e.printStackTrace();
        return FitStatus.TOO_MANY_ITERATIONS;
    } catch (TooManyEvaluationsException e) {
        //e.printStackTrace();
        return FitStatus.TOO_MANY_EVALUATIONS;
    } catch (ConvergenceException e) {
        //System.out.printf("Singular non linear model = %s\n", e.getMessage());
        return FitStatus.SINGULAR_NON_LINEAR_MODEL;
    } catch (BFGSOptimizer.LineSearchRoundoffException e) {
        //e.printStackTrace();
        return FitStatus.FAILED_TO_CONVERGE;
    } catch (Exception e) {
        //System.out.printf("Unknown error = %s\n", e.getMessage());
        e.printStackTrace();
        return FitStatus.UNKNOWN;
    } finally {
        if (baseOptimiser != null) {
            iterations += baseOptimiser.getIterations();
            evaluations += baseOptimiser.getEvaluations();
        }
    }
    // Check this as likelihood functions can go wrong
    if (Double.isInfinite(value) || Double.isNaN(value))
        return FitStatus.INVALID_LIKELIHOOD;
    return FitStatus.OK;
}

Example 12 with PointValuePair

use of org.apache.commons.math3.optim.PointValuePair in project GDSC-SMLM by aherbert.

the class PCPALMClusters method fitBinomial.

/**
	 * Fit a zero-truncated Binomial to the cumulative histogram
	 * 
	 * @param histogramData
	 * @return
	 */
private double[] fitBinomial(HistogramData histogramData) {
    // Get the mean and sum of the input histogram
    double mean;
    double sum = 0;
    count = 0;
    for (int i = 0; i < histogramData.histogram[1].length; i++) {
        count += histogramData.histogram[1][i];
        sum += histogramData.histogram[1][i] * i;
    }
    mean = sum / count;
    String name = "Zero-truncated Binomial distribution";
    Utils.log("Mean cluster size = %s", Utils.rounded(mean));
    Utils.log("Fitting cumulative " + name);
    // Convert to a normalised double array for the binomial fitter
    double[] histogram = new double[histogramData.histogram[1].length];
    for (int i = 0; i < histogramData.histogram[1].length; i++) histogram[i] = histogramData.histogram[1][i] / count;
    // Plot the cumulative histogram
    String title = TITLE + " Cumulative Distribution";
    Plot2 plot = null;
    if (showCumulativeHistogram) {
        // Create a cumulative histogram for fitting
        double[] cumulativeHistogram = new double[histogram.length];
        sum = 0;
        for (int i = 0; i < histogram.length; i++) {
            sum += histogram[i];
            cumulativeHistogram[i] = sum;
        }
        double[] values = Utils.newArray(histogram.length, 0.0, 1.0);
        plot = new Plot2(title, "N", "Cumulative Probability", values, cumulativeHistogram);
        plot.setLimits(0, histogram.length - 1, 0, 1.05);
        plot.addPoints(values, cumulativeHistogram, Plot2.CIRCLE);
        Utils.display(title, plot);
    }
    // Do fitting for different N
    double bestSS = Double.POSITIVE_INFINITY;
    double[] parameters = null;
    int worse = 0;
    int N = histogram.length - 1;
    int min = minN;
    final boolean customRange = (minN > 1) || (maxN > 0);
    if (min > N)
        min = N;
    if (maxN > 0 && N > maxN)
        N = maxN;
    Utils.log("Fitting N from %d to %d%s", min, N, (customRange) ? " (custom-range)" : "");
    // Since varying the N should be done in integer steps do this
    // for n=1,2,3,... until the SS peaks then falls off (is worse then the best 
    // score several times in succession)
    BinomialFitter bf = new BinomialFitter(new IJLogger());
    bf.setMaximumLikelihood(maximumLikelihood);
    for (int n = min; n <= N; n++) {
        PointValuePair solution = bf.fitBinomial(histogram, mean, n, true);
        if (solution == null)
            continue;
        double p = solution.getPointRef()[0];
        Utils.log("Fitted %s : N=%d, p=%s. SS=%g", name, n, Utils.rounded(p), solution.getValue());
        if (bestSS > solution.getValue()) {
            bestSS = solution.getValue();
            parameters = new double[] { n, p };
            worse = 0;
        } else if (bestSS < Double.POSITIVE_INFINITY) {
            if (++worse >= 3)
                break;
        }
        if (showCumulativeHistogram)
            addToPlot(n, p, title, plot, new Color((float) n / N, 0, 1f - (float) n / N));
    }
    // Add best it in magenta
    if (showCumulativeHistogram && parameters != null)
        addToPlot((int) parameters[0], parameters[1], title, plot, Color.magenta);
    return parameters;
}

Example 13 with PointValuePair

use of org.apache.commons.math3.optim.PointValuePair in project GDSC-SMLM by aherbert.

the class PCPALMFitting method fitEmulsionModel.

/**
	 * Fits the correlation curve with r>0 to the clustered model using the estimated density and precision. Parameters
	 * must be fit within a tolerance of the starting values.
	 * 
	 * @param gr
	 * @param sigmaS
	 *            The estimated precision
	 * @param proteinDensity
	 *            The estimated protein density
	 * @return The fitted parameters [precision, density, clusterRadius, clusterDensity]
	 */
private double[] fitEmulsionModel(double[][] gr, double sigmaS, double proteinDensity, String resultColour) {
    final EmulsionModelFunctionGradient function = new EmulsionModelFunctionGradient();
    emulsionModel = function;
    log("Fitting %s: Estimated precision = %f nm, estimated protein density = %g um^-2", emulsionModel.getName(), sigmaS, proteinDensity * 1e6);
    emulsionModel.setLogging(true);
    for (int i = offset; i < gr[0].length; i++) {
        // Only fit the curve above the estimated resolution (points below it will be subject to error)
        if (gr[0][i] > sigmaS * fitAboveEstimatedPrecision)
            emulsionModel.addPoint(gr[0][i], gr[1][i]);
    }
    double[] parameters;
    // The model is: sigma, density, range, amplitude, alpha
    double[] initialSolution = new double[] { sigmaS, proteinDensity, sigmaS * 5, 1, sigmaS * 5 };
    int evaluations = 0;
    // Constrain the fitting to be close to the estimated precision (sigmaS) and protein density.
    // LVM fitting does not support constrained fitting so use a bounded optimiser.
    SumOfSquaresModelFunction emulsionModelMulti = new SumOfSquaresModelFunction(emulsionModel);
    double[] x = emulsionModelMulti.x;
    double[] y = emulsionModelMulti.y;
    // Range should be equal to the first time the g(r) curve crosses 1
    for (int i = 0; i < x.length; i++) if (y[i] < 1) {
        initialSolution[4] = initialSolution[2] = (i > 0) ? (x[i - 1] + x[i]) * 0.5 : x[i];
        break;
    }
    // Put some bounds around the initial guess. Use the fitting tolerance (in %) if provided.
    double limit = (fittingTolerance > 0) ? 1 + fittingTolerance / 100 : 2;
    double[] lB = new double[] { initialSolution[0] / limit, initialSolution[1] / limit, 0, 0, 0 };
    // The amplitude and range should not extend beyond the limits of the g(r) curve.
    // TODO - Find out the expected range for the alpha parameter.  
    double[] uB = new double[] { initialSolution[0] * limit, initialSolution[1] * limit, Maths.max(x), Maths.max(gr[1]), Maths.max(x) * 2 };
    log("Fitting %s using a bounded search: %s < precision < %s & %s < density < %s", emulsionModel.getName(), Utils.rounded(lB[0], 4), Utils.rounded(uB[0], 4), Utils.rounded(lB[1] * 1e6, 4), Utils.rounded(uB[1] * 1e6, 4));
    PointValuePair constrainedSolution = runBoundedOptimiser(gr, initialSolution, lB, uB, emulsionModelMulti);
    if (constrainedSolution == null)
        return null;
    parameters = constrainedSolution.getPointRef();
    evaluations = boundedEvaluations;
    // Refit using a LVM  
    if (useLSE) {
        log("Re-fitting %s using a gradient optimisation", emulsionModel.getName());
        LevenbergMarquardtOptimizer optimizer = new LevenbergMarquardtOptimizer();
        Optimum lvmSolution;
        try {
            //@formatter:off
            LeastSquaresProblem problem = new LeastSquaresBuilder().maxEvaluations(Integer.MAX_VALUE).maxIterations(3000).start(parameters).target(function.getY()).weight(new DiagonalMatrix(function.getWeights())).model(function, new MultivariateMatrixFunction() {

                public double[][] value(double[] point) throws IllegalArgumentException {
                    return function.jacobian(point);
                }
            }).build();
            //@formatter:on
            lvmSolution = optimizer.optimize(problem);
            evaluations += lvmSolution.getEvaluations();
            double ss = lvmSolution.getResiduals().dotProduct(lvmSolution.getResiduals());
            if (ss < constrainedSolution.getValue()) {
                log("Re-fitting %s improved the SS from %s to %s (-%s%%)", emulsionModel.getName(), Utils.rounded(constrainedSolution.getValue(), 4), Utils.rounded(ss, 4), Utils.rounded(100 * (constrainedSolution.getValue() - ss) / constrainedSolution.getValue(), 4));
                parameters = lvmSolution.getPoint().toArray();
            }
        } catch (TooManyIterationsException e) {
            log("Failed to re-fit %s: Too many iterations (%s)", emulsionModel.getName(), e.getMessage());
        } catch (ConvergenceException e) {
            log("Failed to re-fit %s: %s", emulsionModel.getName(), e.getMessage());
        }
    }
    emulsionModel.setLogging(false);
    // Ensure the width is positive
    parameters[0] = Math.abs(parameters[0]);
    //parameters[2] = Math.abs(parameters[2]);
    double ss = 0;
    double[] obs = emulsionModel.getY();
    double[] exp = emulsionModel.value(parameters);
    for (int i = 0; i < obs.length; i++) ss += (obs[i] - exp[i]) * (obs[i] - exp[i]);
    ic3 = Maths.getAkaikeInformationCriterionFromResiduals(ss, emulsionModel.size(), parameters.length);
    final double fitSigmaS = parameters[0];
    final double fitProteinDensity = parameters[1];
    //The radius of the cluster domain
    final double domainRadius = parameters[2];
    //The density of the cluster domain
    final double domainDensity = parameters[3];
    //The coherence length between circles
    final double coherence = parameters[4];
    // This is from the PC-PALM paper. It may not be correct for the emulsion model.
    final double nCluster = 2 * domainDensity * Math.PI * domainRadius * domainRadius * fitProteinDensity;
    double e1 = parameterDrift(sigmaS, fitSigmaS);
    double e2 = parameterDrift(proteinDensity, fitProteinDensity);
    log("  %s fit: SS = %f. cAIC = %f. %d evaluations", emulsionModel.getName(), ss, ic3, evaluations);
    log("  %s parameters:", emulsionModel.getName());
    log("    Average precision = %s nm (%s%%)", Utils.rounded(fitSigmaS, 4), Utils.rounded(e1, 4));
    log("    Average protein density = %s um^-2 (%s%%)", Utils.rounded(fitProteinDensity * 1e6, 4), Utils.rounded(e2, 4));
    log("    Domain radius = %s nm", Utils.rounded(domainRadius, 4));
    log("    Domain density = %s", Utils.rounded(domainDensity, 4));
    log("    Domain coherence = %s", Utils.rounded(coherence, 4));
    log("    nCluster = %s", Utils.rounded(nCluster, 4));
    // Check the fitted parameters are within tolerance of the initial estimates
    valid2 = true;
    if (fittingTolerance > 0 && (Math.abs(e1) > fittingTolerance || Math.abs(e2) > fittingTolerance)) {
        log("  Failed to fit %s within tolerance (%s%%): Average precision = %f nm (%s%%), average protein density = %g um^-2 (%s%%)", emulsionModel.getName(), Utils.rounded(fittingTolerance, 4), fitSigmaS, Utils.rounded(e1, 4), fitProteinDensity * 1e6, Utils.rounded(e2, 4));
        valid2 = false;
    }
    // Check extra parameters. Domain radius should be higher than the precision. Density should be positive
    if (domainRadius < fitSigmaS) {
        log("  Failed to fit %s: Domain radius is smaller than the average precision (%s < %s)", emulsionModel.getName(), Utils.rounded(domainRadius, 4), Utils.rounded(fitSigmaS, 4));
        valid2 = false;
    }
    if (domainDensity < 0) {
        log("  Failed to fit %s: Domain density is negative (%s)", emulsionModel.getName(), Utils.rounded(domainDensity, 4));
        valid2 = false;
    }
    if (ic3 > ic1) {
        log("  Failed to fit %s - Information Criterion has increased %s%%", emulsionModel.getName(), Utils.rounded((100 * (ic3 - ic1) / ic1), 4));
        valid2 = false;
    }
    addResult(emulsionModel.getName(), resultColour, valid2, fitSigmaS, fitProteinDensity, domainRadius, domainDensity, nCluster, coherence, ic3);
    return parameters;
}

Example 14 with PointValuePair

use of org.apache.commons.math3.optim.PointValuePair in project vcell by virtualcell.

the class FitTimeSeries method fitToGaussian.

static GaussianFitResults fitToGaussian(double init_center_i, double init_center_j, double init_radius2, FloatImage image) {
    // 
    // do some optimization on the image (fitting to a Gaussian)
    // set initial guesses from ROI operation.
    // 
    ISize imageSize = image.getISize();
    final int num_i = imageSize.getX();
    final int num_j = imageSize.getY();
    final float[] floatPixels = image.getFloatPixels();
    // 
    // initial guess based on previous fit of ROI
    // do gaussian fit in index space for center and standard deviation (later to translate it back to world coordinates)
    // 
    final int window_size = (int) Math.sqrt(init_radius2) * 4;
    // final int window_min_i = 0;       // (int) Math.max(0, Math.floor(init_center_i - window_size/2));
    // final int window_max_i = num_i-1; // (int) Math.min(num_i-1, Math.ceil(init_center_i + window_size/2));
    // final int window_min_j = 0;       // (int) Math.max(0, Math.floor(init_center_j - window_size/2));
    // final int window_max_j = num_j-1; // (int) Math.min(num_j-1, Math.ceil(init_center_j + window_size/2));
    final int window_min_i = (int) Math.max(0, Math.floor(init_center_i - window_size / 2));
    final int window_max_i = (int) Math.min(num_i - 1, Math.ceil(init_center_i + window_size / 2));
    final int window_min_j = (int) Math.max(0, Math.floor(init_center_j - window_size / 2));
    final int window_max_j = (int) Math.min(num_j - 1, Math.ceil(init_center_j + window_size / 2));
    final int PARAM_INDEX_CENTER_I = 0;
    final int PARAM_INDEX_CENTER_J = 1;
    final int PARAM_INDEX_K = 2;
    final int PARAM_INDEX_HIGH = 3;
    final int PARAM_INDEX_RADIUS_SQUARED = 4;
    final int NUM_PARAMETERS = 5;
    double[] initParameters = new double[NUM_PARAMETERS];
    initParameters[PARAM_INDEX_CENTER_I] = init_center_i;
    initParameters[PARAM_INDEX_CENTER_J] = init_center_j;
    initParameters[PARAM_INDEX_HIGH] = 1.0;
    initParameters[PARAM_INDEX_K] = 10;
    initParameters[PARAM_INDEX_RADIUS_SQUARED] = init_radius2;
    PowellOptimizer optimizer = new PowellOptimizer(1e-4, 1e-1);
    MultivariateFunction func = new MultivariateFunction() {

        @Override
        public double value(double[] point) {
            double center_i = point[PARAM_INDEX_CENTER_I];
            double center_j = point[PARAM_INDEX_CENTER_J];
            double high = point[PARAM_INDEX_HIGH];
            double K = point[PARAM_INDEX_K];
            double radius2 = point[PARAM_INDEX_RADIUS_SQUARED];
            double error2 = 0;
            for (int j = window_min_j; j <= window_max_j; j++) {
                // double y = j - center_j;
                double y = j;
                for (int i = window_min_i; i <= window_max_i; i++) {
                    // double x = i - center_i;
                    double x = i;
                    double modelValue = high - FastMath.exp(-K * FastMath.exp(-2 * (x * x + y * y) / radius2));
                    double imageValue = floatPixels[j * num_i + i];
                    double error = modelValue - imageValue;
                    error2 += error * error;
                }
            }
            System.out.println(new GaussianFitResults(center_i, center_j, radius2, K, high, error2));
            return error2;
        }
    };
    PointValuePair pvp = optimizer.optimize(new ObjectiveFunction(func), new InitialGuess(initParameters), new MaxEval(100000), GoalType.MINIMIZE);
    double[] fittedParamValues = pvp.getPoint();
    double fitted_center_i = fittedParamValues[PARAM_INDEX_CENTER_I];
    double fitted_center_j = fittedParamValues[PARAM_INDEX_CENTER_J];
    double fitted_radius2 = fittedParamValues[PARAM_INDEX_RADIUS_SQUARED];
    double fitted_K = fittedParamValues[PARAM_INDEX_K];
    double fitted_high = fittedParamValues[PARAM_INDEX_HIGH];
    double objectiveFunctionValue = pvp.getValue();
    return new GaussianFitResults(fitted_center_i, fitted_center_j, fitted_radius2, fitted_K, fitted_high, objectiveFunctionValue);
}

Example 15 with PointValuePair

use of org.apache.commons.math3.optim.PointValuePair in project GDSC-SMLM by aherbert.

the class PCPALMFitting method fitClusteredModel.

/**
	 * Fits the correlation curve with r>0 to the clustered model using the estimated density and precision. Parameters
	 * must be fit within a tolerance of the starting values.
	 * 
	 * @param gr
	 * @param sigmaS
	 *            The estimated precision
	 * @param proteinDensity
	 *            The estimated protein density
	 * @return The fitted parameters [precision, density, clusterRadius, clusterDensity]
	 */
private double[] fitClusteredModel(double[][] gr, double sigmaS, double proteinDensity, String resultColour) {
    final ClusteredModelFunctionGradient function = new ClusteredModelFunctionGradient();
    clusteredModel = function;
    log("Fitting %s: Estimated precision = %f nm, estimated protein density = %g um^-2", clusteredModel.getName(), sigmaS, proteinDensity * 1e6);
    clusteredModel.setLogging(true);
    for (int i = offset; i < gr[0].length; i++) {
        // Only fit the curve above the estimated resolution (points below it will be subject to error)
        if (gr[0][i] > sigmaS * fitAboveEstimatedPrecision)
            clusteredModel.addPoint(gr[0][i], gr[1][i]);
    }
    double[] parameters;
    // The model is: sigma, density, range, amplitude
    double[] initialSolution = new double[] { sigmaS, proteinDensity, sigmaS * 5, 1 };
    int evaluations = 0;
    // Constrain the fitting to be close to the estimated precision (sigmaS) and protein density.
    // LVM fitting does not support constrained fitting so use a bounded optimiser.
    SumOfSquaresModelFunction clusteredModelMulti = new SumOfSquaresModelFunction(clusteredModel);
    double[] x = clusteredModelMulti.x;
    // Put some bounds around the initial guess. Use the fitting tolerance (in %) if provided.
    double limit = (fittingTolerance > 0) ? 1 + fittingTolerance / 100 : 2;
    double[] lB = new double[] { initialSolution[0] / limit, initialSolution[1] / limit, 0, 0 };
    // The amplitude and range should not extend beyond the limits of the g(r) curve.
    double[] uB = new double[] { initialSolution[0] * limit, initialSolution[1] * limit, Maths.max(x), Maths.max(gr[1]) };
    log("Fitting %s using a bounded search: %s < precision < %s & %s < density < %s", clusteredModel.getName(), Utils.rounded(lB[0], 4), Utils.rounded(uB[0], 4), Utils.rounded(lB[1] * 1e6, 4), Utils.rounded(uB[1] * 1e6, 4));
    PointValuePair constrainedSolution = runBoundedOptimiser(gr, initialSolution, lB, uB, clusteredModelMulti);
    if (constrainedSolution == null)
        return null;
    parameters = constrainedSolution.getPointRef();
    evaluations = boundedEvaluations;
    // Refit using a LVM  
    if (useLSE) {
        log("Re-fitting %s using a gradient optimisation", clusteredModel.getName());
        LevenbergMarquardtOptimizer optimizer = new LevenbergMarquardtOptimizer();
        Optimum lvmSolution;
        try {
            //@formatter:off
            LeastSquaresProblem problem = new LeastSquaresBuilder().maxEvaluations(Integer.MAX_VALUE).maxIterations(3000).start(parameters).target(function.getY()).weight(new DiagonalMatrix(function.getWeights())).model(function, new MultivariateMatrixFunction() {

                public double[][] value(double[] point) throws IllegalArgumentException {
                    return function.jacobian(point);
                }
            }).build();
            //@formatter:on
            lvmSolution = optimizer.optimize(problem);
            evaluations += lvmSolution.getEvaluations();
            double ss = lvmSolution.getResiduals().dotProduct(lvmSolution.getResiduals());
            if (ss < constrainedSolution.getValue()) {
                log("Re-fitting %s improved the SS from %s to %s (-%s%%)", clusteredModel.getName(), Utils.rounded(constrainedSolution.getValue(), 4), Utils.rounded(ss, 4), Utils.rounded(100 * (constrainedSolution.getValue() - ss) / constrainedSolution.getValue(), 4));
                parameters = lvmSolution.getPoint().toArray();
            }
        } catch (TooManyIterationsException e) {
            log("Failed to re-fit %s: Too many iterations (%s)", clusteredModel.getName(), e.getMessage());
        } catch (ConvergenceException e) {
            log("Failed to re-fit %s: %s", clusteredModel.getName(), e.getMessage());
        }
    }
    clusteredModel.setLogging(false);
    // Ensure the width is positive
    parameters[0] = Math.abs(parameters[0]);
    //parameters[2] = Math.abs(parameters[2]);
    double ss = 0;
    double[] obs = clusteredModel.getY();
    double[] exp = clusteredModel.value(parameters);
    for (int i = 0; i < obs.length; i++) ss += (obs[i] - exp[i]) * (obs[i] - exp[i]);
    ic2 = Maths.getAkaikeInformationCriterionFromResiduals(ss, clusteredModel.size(), parameters.length);
    final double fitSigmaS = parameters[0];
    final double fitProteinDensity = parameters[1];
    //The radius of the cluster domain
    final double domainRadius = parameters[2];
    //The density of the cluster domain
    final double domainDensity = parameters[3];
    // This is from the PC-PALM paper. However that paper fits the g(r)protein exponential convolved in 2D
    // with the g(r)PSF. In this method we have just fit the exponential
    final double nCluster = 2 * domainDensity * Math.PI * domainRadius * domainRadius * fitProteinDensity;
    double e1 = parameterDrift(sigmaS, fitSigmaS);
    double e2 = parameterDrift(proteinDensity, fitProteinDensity);
    log("  %s fit: SS = %f. cAIC = %f. %d evaluations", clusteredModel.getName(), ss, ic2, evaluations);
    log("  %s parameters:", clusteredModel.getName());
    log("    Average precision = %s nm (%s%%)", Utils.rounded(fitSigmaS, 4), Utils.rounded(e1, 4));
    log("    Average protein density = %s um^-2 (%s%%)", Utils.rounded(fitProteinDensity * 1e6, 4), Utils.rounded(e2, 4));
    log("    Domain radius = %s nm", Utils.rounded(domainRadius, 4));
    log("    Domain density = %s", Utils.rounded(domainDensity, 4));
    log("    nCluster = %s", Utils.rounded(nCluster, 4));
    // Check the fitted parameters are within tolerance of the initial estimates
    valid2 = true;
    if (fittingTolerance > 0 && (Math.abs(e1) > fittingTolerance || Math.abs(e2) > fittingTolerance)) {
        log("  Failed to fit %s within tolerance (%s%%): Average precision = %f nm (%s%%), average protein density = %g um^-2 (%s%%)", clusteredModel.getName(), Utils.rounded(fittingTolerance, 4), fitSigmaS, Utils.rounded(e1, 4), fitProteinDensity * 1e6, Utils.rounded(e2, 4));
        valid2 = false;
    }
    // Check extra parameters. Domain radius should be higher than the precision. Density should be positive
    if (domainRadius < fitSigmaS) {
        log("  Failed to fit %s: Domain radius is smaller than the average precision (%s < %s)", clusteredModel.getName(), Utils.rounded(domainRadius, 4), Utils.rounded(fitSigmaS, 4));
        valid2 = false;
    }
    if (domainDensity < 0) {
        log("  Failed to fit %s: Domain density is negative (%s)", clusteredModel.getName(), Utils.rounded(domainDensity, 4));
        valid2 = false;
    }
    if (ic2 > ic1) {
        log("  Failed to fit %s - Information Criterion has increased %s%%", clusteredModel.getName(), Utils.rounded((100 * (ic2 - ic1) / ic1), 4));
        valid2 = false;
    }
    addResult(clusteredModel.getName(), resultColour, valid2, fitSigmaS, fitProteinDensity, domainRadius, domainDensity, nCluster, 0, ic2);
    return parameters;
}