use of org.apache.commons.math3.optim.nonlinear.scalar.noderiv.BOBYQAOptimizer in project GDSC-SMLM by aherbert.
the class BinomialFitter method fitBinomial.
/**
* Fit the binomial distribution (n,p) to the cumulative histogram. Performs fitting assuming a
* fixed n value and attempts to optimise p.
*
* @param histogram The input histogram
* @param mean The histogram mean (used to estimate p). Calculated if NaN.
* @param n The n to evaluate
* @param zeroTruncated True if the model should ignore n=0 (zero-truncated binomial)
* @return The best fit (n, p)
* @throws IllegalArgumentException If any of the input data values are negative
* @throws IllegalArgumentException If any fitting a zero truncated binomial and there are no
* values above zero
*/
public PointValuePair fitBinomial(double[] histogram, double mean, int n, boolean zeroTruncated) {
if (Double.isNaN(mean)) {
mean = getMean(histogram);
}
if (zeroTruncated && histogram[0] > 0) {
log("Fitting zero-truncated histogram but there are zero values - " + "Renormalising to ignore zero");
double cumul = 0;
for (int i = 1; i < histogram.length; i++) {
cumul += histogram[i];
}
if (cumul == 0) {
throw new IllegalArgumentException("Fitting zero-truncated histogram but there are no non-zero values");
}
histogram[0] = 0;
for (int i = 1; i < histogram.length; i++) {
histogram[i] /= cumul;
}
}
final int nFittedPoints = Math.min(histogram.length, n + 1) - ((zeroTruncated) ? 1 : 0);
if (nFittedPoints < 1) {
log("No points to fit (%d): Histogram.length = %d, n = %d, zero-truncated = %b", nFittedPoints, histogram.length, n, zeroTruncated);
return null;
}
// The model is only fitting the probability p
// For a binomial n*p = mean => p = mean/n
final double[] initialSolution = new double[] { Math.min(mean / n, 1) };
// Create the function
final BinomialModelFunction function = new BinomialModelFunction(histogram, n, zeroTruncated);
final double[] lB = new double[1];
final double[] uB = new double[] { 1 };
final SimpleBounds bounds = new SimpleBounds(lB, uB);
// Fit
// CMAESOptimizer or BOBYQAOptimizer support bounds
// CMAESOptimiser based on Matlab code:
// https://www.lri.fr/~hansen/cmaes.m
// Take the defaults from the Matlab documentation
final int maxIterations = 2000;
final double stopFitness = 0;
final boolean isActiveCma = true;
final int diagonalOnly = 0;
final int checkFeasableCount = 1;
final RandomGenerator random = new RandomGeneratorAdapter(UniformRandomProviders.create());
final boolean generateStatistics = false;
final ConvergenceChecker<PointValuePair> checker = new SimpleValueChecker(1e-6, 1e-10);
// The sigma determines the search range for the variables. It should be 1/3 of the initial
// search region.
final OptimizationData sigma = new CMAESOptimizer.Sigma(new double[] { (uB[0] - lB[0]) / 3 });
final OptimizationData popSize = new CMAESOptimizer.PopulationSize((int) (4 + Math.floor(3 * Math.log(2))));
try {
PointValuePair solution = null;
boolean noRefit = maximumLikelihood;
if (n == 1 && zeroTruncated) {
// No need to fit
solution = new PointValuePair(new double[] { 1 }, 0);
noRefit = true;
} else {
final GoalType goalType = (maximumLikelihood) ? GoalType.MAXIMIZE : GoalType.MINIMIZE;
// Iteratively fit
final CMAESOptimizer opt = new CMAESOptimizer(maxIterations, stopFitness, isActiveCma, diagonalOnly, checkFeasableCount, random, generateStatistics, checker);
for (int iteration = 0; iteration <= fitRestarts; iteration++) {
try {
// Start from the initial solution
final PointValuePair result = opt.optimize(new InitialGuess(initialSolution), new ObjectiveFunction(function), goalType, bounds, sigma, popSize, new MaxIter(maxIterations), new MaxEval(maxIterations * 2));
// opt.getEvaluations());
if (solution == null || result.getValue() < solution.getValue()) {
solution = result;
}
} catch (final TooManyEvaluationsException | TooManyIterationsException ex) {
// No solution
}
if (solution == null) {
continue;
}
try {
// Also restart from the current optimum
final PointValuePair result = opt.optimize(new InitialGuess(solution.getPointRef()), new ObjectiveFunction(function), goalType, bounds, sigma, popSize, new MaxIter(maxIterations), new MaxEval(maxIterations * 2));
// opt.getEvaluations());
if (result.getValue() < solution.getValue()) {
solution = result;
}
} catch (final TooManyEvaluationsException | TooManyIterationsException ex) {
// No solution
}
}
if (solution == null) {
return null;
}
}
if (noRefit) {
// Although we fit the log-likelihood, return the sum-of-squares to allow
// comparison across different n
final double p = solution.getPointRef()[0];
double ss = 0;
final double[] obs = function.pvalues;
final double[] exp = function.getP(p);
for (int i = 0; i < obs.length; i++) {
ss += (obs[i] - exp[i]) * (obs[i] - exp[i]);
}
return new PointValuePair(solution.getPointRef(), ss);
// We can do a LVM refit if the number of fitted points is more than 1.
} else if (nFittedPoints > 1) {
// Improve SS fit with a gradient based LVM optimizer
final LevenbergMarquardtOptimizer optimizer = new LevenbergMarquardtOptimizer();
try {
final BinomialModelFunctionGradient gradientFunction = new BinomialModelFunctionGradient(histogram, n, zeroTruncated);
// @formatter:off
final LeastSquaresProblem problem = new LeastSquaresBuilder().maxEvaluations(Integer.MAX_VALUE).maxIterations(3000).start(solution.getPointRef()).target(gradientFunction.pvalues).weight(new DiagonalMatrix(gradientFunction.getWeights())).model(gradientFunction, gradientFunction::jacobian).build();
// @formatter:on
final Optimum lvmSolution = optimizer.optimize(problem);
// Check the pValue is valid since the LVM is not bounded.
final double p = lvmSolution.getPoint().getEntry(0);
if (p <= 1 && p >= 0) {
// True if the weights are 1
final double ss = lvmSolution.getResiduals().dotProduct(lvmSolution.getResiduals());
// ss += (obs[i] - exp[i]) * (obs[i] - exp[i]);
if (ss < solution.getValue()) {
// MathUtils.rounded(100 * (solution.getValue() - ss) / solution.getValue(), 4));
return new PointValuePair(lvmSolution.getPoint().toArray(), ss);
}
}
} catch (final TooManyIterationsException ex) {
log("Failed to re-fit: Too many iterations: %s", ex.getMessage());
} catch (final ConvergenceException ex) {
log("Failed to re-fit: %s", ex.getMessage());
} catch (final Exception ex) {
// Ignore this ...
}
}
return solution;
} catch (final RuntimeException ex) {
log("Failed to fit Binomial distribution with N=%d : %s", n, ex.getMessage());
}
return null;
}
use of org.apache.commons.math3.optim.nonlinear.scalar.noderiv.BOBYQAOptimizer in project GDSC-SMLM by aherbert.
the class MaximumLikelihoodFitter method computeFit.
@Override
public FitStatus computeFit(double[] y, double[] fx, double[] a, double[] parametersVariance) {
final int n = y.length;
final LikelihoodWrapper maximumLikelihoodFunction = createLikelihoodWrapper((NonLinearFunction) function, n, y, a);
@SuppressWarnings("rawtypes") BaseOptimizer baseOptimiser = null;
try {
final 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
// Background: see Numerical Recipes 10.5 (Direction Set (Powell's) method).
// The optimiser could be extended to 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 = Math.sqrt(relativeThreshold);
// final double lineAbs = Math.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;
final 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
final 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)));
final double[] solution = adapter.unboundedToBounded(optimum.getPointRef());
optimum = new PointValuePair(solution, optimum.getValue());
} else {
if (powellFunction == null) {
powellFunction = new MultivariateLikelihood(maximumLikelihoodFunction);
}
// Update the maximum likelihood function in the Powell function wrapper
powellFunction.fun = maximumLikelihoodFunction;
final OptimizationData positionChecker = null;
// new org.apache.commons.math3.optim.PositionChecker(relativeThreshold,
// absoluteThreshold);
SimpleBounds simpleBounds = null;
if (powellFunction.isMapped()) {
final 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);
final 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.
final int numberOfInterpolationpoints = this.getNumberOfFittedParameters() + 2;
final 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.
// The CMAESOptimiser is based on Matlab code:
// https://www.lri.fr/~hansen/cmaes.m
// Take the defaults from the Matlab documentation
final double stopFitness = 0;
final boolean isActiveCma = true;
final int diagonalOnly = 0;
final int checkFeasableCount = 1;
final RandomGenerator random = new RandomGeneratorAdapter(UniformRandomProviders.create());
final boolean generateStatistics = false;
// The sigma determines the search range for the variables. It should be 1/3 of the initial
// search region.
final 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 = Math.min(sigma.length * sigma.length * 30, getMaxEvaluations() / 2);
evaluations = 0;
final 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
if (optimum != null) {
data[0] = new InitialGuess(optimum.getPointRef());
}
popSize *= 2;
data[1] = new CMAESOptimizer.PopulationSize(popSize);
}
final CMAESOptimizer o = new CMAESOptimizer(getMaxIterations(), stopFitness, isActiveCma, diagonalOnly, checkFeasableCount, random, generateStatistics, new SimpleValueChecker(relativeThreshold, absoluteThreshold));
baseOptimiser = o;
final PointValuePair result = o.optimize(data);
iterations += o.getIterations();
evaluations += o.getEvaluations();
if (optimum == null || result.getValue() < optimum.getValue()) {
optimum = result;
}
}
// Prevent incrementing the iterations again
baseOptimiser = null;
} 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.
final 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 length = 0;
for (final double d : gradient) {
length += d * d;
}
final double bracketingStep = Math.min(0.001, ((length > 1) ? 1.0 / length : 1));
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));
}
if (optimum == null) {
return FitStatus.FAILED_TO_CONVERGE;
}
final double[] solution = optimum.getPointRef();
setSolution(a, solution);
if (parametersVariance != null) {
// Compute assuming a Poisson process.
// Note:
// If using a Poisson-Gamma-Gaussian model then these will be incorrect.
// However the variance for the position estimates of a 2D PSF can be
// scaled by a factor of 2 as in Mortensen, et al (2010) Nature Methods 7, 377-383, SI 4.3.
// Since the type of function is unknown this cannot be done here.
final FisherInformationMatrix m = new FisherInformationMatrix(maximumLikelihoodFunction.fisherInformation(solution));
setDeviations(parametersVariance, m);
}
// Reverse negative log likelihood for maximum likelihood score
value = -optimum.getValue();
} catch (final TooManyIterationsException ex) {
return FitStatus.TOO_MANY_ITERATIONS;
} catch (final TooManyEvaluationsException ex) {
return FitStatus.TOO_MANY_EVALUATIONS;
} catch (final ConvergenceException ex) {
// Occurs when QR decomposition fails - mark as a singular non-linear model (no solution)
return FitStatus.SINGULAR_NON_LINEAR_MODEL;
} catch (final Exception ex) {
Logger.getLogger(getClass().getName()).log(Level.SEVERE, "Failed to fit", ex);
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;
}
use of org.apache.commons.math3.optim.nonlinear.scalar.noderiv.BOBYQAOptimizer in project engineblock by engineblock.
the class TestOptimoExperiments method testNewAlgo.
@Test
public void testNewAlgo() {
MultivariateFunction m = new SumDeltaNoise();
// MultivariateDifferentiableFunction mvdf =FunctionUtils.
// MultivariateVectorFunction mvf = new GradientFunction(mvdf);
// ObjectiveFunctionGradient ofg = new ObjectiveFunctionGradient(mvf);
SimpleBounds bounds = new SimpleBounds(new double[] { 0.0d, 0.0d, 0.0d }, new double[] { 1E9, 1E9, 1E9 });
List<OptimizationData> od = List.of(new ObjectiveFunction(m), GoalType.MAXIMIZE, new InitialGuess(new double[] { 1.0, 1.0, 1.0 }), new MaxEval(1000), bounds);
BOBYQAOptimizer mo = new BOBYQAOptimizer(9, 1000.0, 1.0);
PointValuePair result = mo.optimize(od.toArray(new OptimizationData[0]));
System.out.println("point:" + Arrays.toString(result.getPoint()) + " value=" + m.value(result.getPoint()));
}
use of org.apache.commons.math3.optim.nonlinear.scalar.noderiv.BOBYQAOptimizer in project tetrad by cmu-phil.
the class GeneralizedSemEstimator method optimize.
private double[] optimize(MultivariateFunction function, double[] values, int optimizer) {
PointValuePair pair;
if (optimizer == 1) {
// 0.01, 0.000001
// 2.0D * FastMath.ulp(1.0D), 1e-8
MultivariateOptimizer search = new PowellOptimizer(1e-7, 1e-7);
pair = search.optimize(new InitialGuess(values), new ObjectiveFunction(function), GoalType.MINIMIZE, new MaxEval(100000));
} else if (optimizer == 2) {
MultivariateOptimizer search = new SimplexOptimizer(1e-7, 1e-7);
pair = search.optimize(new InitialGuess(values), new ObjectiveFunction(function), GoalType.MINIMIZE, new MaxEval(100000), new NelderMeadSimplex(values.length));
} else if (optimizer == 3) {
int dim = values.length;
int additionalInterpolationPoints = 0;
final int numIterpolationPoints = 2 * dim + 1 + additionalInterpolationPoints;
BOBYQAOptimizer search = new BOBYQAOptimizer(numIterpolationPoints);
pair = search.optimize(new MaxEval(100000), new ObjectiveFunction(function), GoalType.MINIMIZE, new InitialGuess(values), SimpleBounds.unbounded(dim));
} else if (optimizer == 4) {
MultivariateOptimizer search = new CMAESOptimizer(3000000, .05, false, 0, 0, new MersenneTwister(), false, new SimplePointChecker<PointValuePair>(0.5, 0.5));
pair = search.optimize(new MaxEval(30000), new ObjectiveFunction(function), GoalType.MINIMIZE, new InitialGuess(values), new CMAESOptimizer.Sigma(new double[values.length]), new CMAESOptimizer.PopulationSize(1000));
} else if (optimizer == 5) {
// 0.01, 0.000001
// 2.0D * FastMath.ulp(1.0D), 1e-8
MultivariateOptimizer search = new PowellOptimizer(.05, .05);
pair = search.optimize(new InitialGuess(values), new ObjectiveFunction(function), GoalType.MINIMIZE, new MaxEval(100000));
} else if (optimizer == 6) {
MultivariateOptimizer search = new PowellOptimizer(1e-7, 1e-7);
pair = search.optimize(new InitialGuess(values), new ObjectiveFunction(function), GoalType.MAXIMIZE, new MaxEval(10000));
} else {
throw new IllegalStateException();
}
return pair.getPoint();
}
use of org.apache.commons.math3.optim.nonlinear.scalar.noderiv.BOBYQAOptimizer in project aic-expresso by aic-sri-international.
the class OptimizationWithBOBYQA method findArgopt.
/**
* return the Argopt of a function as a double[].
*/
public double[] findArgopt() {
PointValuePair optimum = optimize(bobyqaOptimizer);
double[] result = optimum.getPoint();
return result;
}
Aggregations