use of org.apache.commons.math3.exception.ConvergenceException in project GDSC-SMLM by aherbert.
the class TraceDiffusion method fitMSD.
/**
* Fit the MSD using a linear fit that must pass through 0,0.
* <p>
* Update the plot by adding the fit line.
*
* @param x
* @param y
* @param title
* @param plot
* @return [D, precision]
*/
private double[] fitMSD(double[] x, double[] y, String title, Plot2 plot) {
// The Weimann paper (Plos One e64287) fits:
// MSD(n dt) = 4D n dt + 4s^2
// n = number of jumps
// dt = time difference between frames
// s = localisation precision
// Thus we should fit an intercept as well.
// From the fit D = gradient / (4*exposureTime)
double D = 0;
double intercept = 0;
double precision = 0;
LevenbergMarquardtOptimizer optimizer = new LevenbergMarquardtOptimizer();
Optimum lvmSolution;
double ic = 0;
// Fit with no intercept
try {
final LinearFunction function = new LinearFunction(x, y, settings.fitLength);
double[] parameters = new double[] { function.guess() };
//@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);
double ss = lvmSolution.getResiduals().dotProduct(lvmSolution.getResiduals());
//double ss = 0;
//double[] obs = function.getY();
//double[] exp = lvmSolution.getValue();
//for (int i = 0; i < obs.length; i++)
// ss += (obs[i] - exp[i]) * (obs[i] - exp[i]);
ic = Maths.getAkaikeInformationCriterionFromResiduals(ss, function.getY().length, 1);
double gradient = lvmSolution.getPoint().getEntry(0);
D = gradient / 4;
Utils.log("Linear fit (%d points) : Gradient = %s, D = %s um^2/s, SS = %s, IC = %s (%d evaluations)", function.getY().length, Utils.rounded(gradient, 4), Utils.rounded(D, 4), Utils.rounded(ss), Utils.rounded(ic), lvmSolution.getEvaluations());
} catch (TooManyIterationsException e) {
Utils.log("Failed to fit : Too many iterations (%s)", e.getMessage());
} catch (ConvergenceException e) {
Utils.log("Failed to fit : %s", e.getMessage());
}
// Fit with intercept.
// Optionally include the intercept (which is the estimated precision).
boolean fitIntercept = true;
try {
final LinearFunctionWithIntercept function = new LinearFunctionWithIntercept(x, y, settings.fitLength, fitIntercept);
//@formatter:off
LeastSquaresProblem problem = new LeastSquaresBuilder().maxEvaluations(Integer.MAX_VALUE).maxIterations(3000).start(function.guess()).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);
double ss = lvmSolution.getResiduals().dotProduct(lvmSolution.getResiduals());
//double ss = 0;
//double[] obs = function.getY();
//double[] exp = lvmSolution.getValue();
//for (int i = 0; i < obs.length; i++)
// ss += (obs[i] - exp[i]) * (obs[i] - exp[i]);
double ic2 = Maths.getAkaikeInformationCriterionFromResiduals(ss, function.getY().length, 2);
double gradient = lvmSolution.getPoint().getEntry(0);
final double s = lvmSolution.getPoint().getEntry(1);
double intercept2 = 4 * s * s;
if (ic2 < ic || debugFitting) {
// Convert fitted precision in um to nm
Utils.log("Linear fit with intercept (%d points) : Gradient = %s, Intercept = %s, D = %s um^2/s, precision = %s nm, SS = %s, IC = %s (%d evaluations)", function.getY().length, Utils.rounded(gradient, 4), Utils.rounded(intercept2, 4), Utils.rounded(gradient / 4, 4), Utils.rounded(s * 1000, 4), Utils.rounded(ss), Utils.rounded(ic2), lvmSolution.getEvaluations());
}
if (lvmSolution == null || ic2 < ic) {
intercept = intercept2;
D = gradient / 4;
precision = s;
}
} catch (TooManyIterationsException e) {
Utils.log("Failed to fit with intercept : Too many iterations (%s)", e.getMessage());
} catch (ConvergenceException e) {
Utils.log("Failed to fit with intercept : %s", e.getMessage());
}
if (settings.msdCorrection) {
// i.e. the intercept is allowed to be a small negative.
try {
// This function fits the jump distance (n) not the time (nt) so update x
double[] x2 = new double[x.length];
for (int i = 0; i < x2.length; i++) x2[i] = x[i] / exposureTime;
final LinearFunctionWithMSDCorrectedIntercept function = new LinearFunctionWithMSDCorrectedIntercept(x2, y, settings.fitLength, fitIntercept);
//@formatter:off
LeastSquaresProblem problem = new LeastSquaresBuilder().maxEvaluations(Integer.MAX_VALUE).maxIterations(3000).start(function.guess()).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);
double ss = lvmSolution.getResiduals().dotProduct(lvmSolution.getResiduals());
//double ss = 0;
//double[] obs = function.getY();
//double[] exp = lvmSolution.getValue();
//for (int i = 0; i < obs.length; i++)
// ss += (obs[i] - exp[i]) * (obs[i] - exp[i]);
double ic2 = Maths.getAkaikeInformationCriterionFromResiduals(ss, function.getY().length, 2);
double gradient = lvmSolution.getPoint().getEntry(0);
final double s = lvmSolution.getPoint().getEntry(1);
double intercept2 = 4 * s * s - gradient / 3;
// Q. Is this working?
// Try fixed precision fitting. Is the gradient correct?
// Revisit all the equations to see if they are wrong.
// Try adding the x[0] datapoint using the precision.
// Change the formula to not be linear at x[0] and to just fit the precision, i.e. the intercept2 = 4 * s * s - gradient / 3 is wrong as the
// equation is not linear below n=1.
// Incorporate the exposure time into the gradient to allow comparison to other fits
gradient /= exposureTime;
if (ic2 < ic || debugFitting) {
// Convert fitted precision in um to nm
Utils.log("Linear fit with MSD corrected intercept (%d points) : Gradient = %s, Intercept = %s, D = %s um^2/s, precision = %s nm, SS = %s, IC = %s (%d evaluations)", function.getY().length, Utils.rounded(gradient, 4), Utils.rounded(intercept2, 4), Utils.rounded(gradient / 4, 4), Utils.rounded(s * 1000, 4), Utils.rounded(ss), Utils.rounded(ic2), lvmSolution.getEvaluations());
}
if (lvmSolution == null || ic2 < ic) {
intercept = intercept2;
D = gradient / 4;
precision = s;
}
} catch (TooManyIterationsException e) {
Utils.log("Failed to fit with intercept : Too many iterations (%s)", e.getMessage());
} catch (ConvergenceException e) {
Utils.log("Failed to fit with intercept : %s", e.getMessage());
}
}
// Add the fit to the plot
if (D > 0) {
plot.setColor(Color.magenta);
plot.drawLine(0, intercept, x[x.length - 1], 4 * D * x[x.length - 1] + intercept);
display(title, plot);
checkTraceDistance(D);
}
return new double[] { D, precision };
}
use of org.apache.commons.math3.exception.ConvergenceException 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;
}
use of org.apache.commons.math3.exception.ConvergenceException 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;
}
use of org.apache.commons.math3.exception.ConvergenceException in project GDSC-SMLM by aherbert.
the class BlinkEstimator method fit.
/**
* Fit the dark time to counts of molecules curve. Only use the first n fitted points.
* <p>
* Calculates:<br/>
* N = The number of photoblinking molecules in the sample<br/>
* nBlink = The average number of blinks per flourophore<br/>
* tOff = The off-time
*
* @param td
* The dark time
* @param ntd
* The counts of molecules
* @param nFittedPoints
* @param log
* Write the fitting results to the ImageJ log window
* @return The fitted parameters [N, nBlink, tOff], or null if no fit was possible
*/
public double[] fit(double[] td, double[] ntd, int nFittedPoints, boolean log) {
blinkingModel = new BlinkingFunction();
blinkingModel.setLogging(true);
for (int i = 0; i < nFittedPoints; i++) blinkingModel.addPoint(td[i], ntd[i]);
// Different convergence thresholds seem to have no effect on the resulting fit, only the number of
// iterations for convergence
double initialStepBoundFactor = 100;
double costRelativeTolerance = 1e-6;
double parRelativeTolerance = 1e-6;
double orthoTolerance = 1e-6;
double threshold = Precision.SAFE_MIN;
LevenbergMarquardtOptimizer optimiser = new LevenbergMarquardtOptimizer(initialStepBoundFactor, costRelativeTolerance, parRelativeTolerance, orthoTolerance, threshold);
try {
double[] obs = blinkingModel.getY();
//@formatter:off
LeastSquaresProblem problem = new LeastSquaresBuilder().maxEvaluations(Integer.MAX_VALUE).maxIterations(1000).start(new double[] { ntd[0], 0.1, td[1] }).target(obs).weight(new DiagonalMatrix(blinkingModel.getWeights())).model(blinkingModel, new MultivariateMatrixFunction() {
public double[][] value(double[] point) throws IllegalArgumentException {
return blinkingModel.jacobian(point);
}
}).build();
//@formatter:on
blinkingModel.setLogging(false);
Optimum optimum = optimiser.optimize(problem);
double[] parameters = optimum.getPoint().toArray();
//double[] exp = blinkingModel.value(parameters);
double mean = 0;
for (double d : obs) mean += d;
mean /= obs.length;
double ssResiduals = 0, ssTotal = 0;
for (int i = 0; i < obs.length; i++) {
//ssResiduals += (obs[i] - exp[i]) * (obs[i] - exp[i]);
ssTotal += (obs[i] - mean) * (obs[i] - mean);
}
// This is true if the weights are 1
ssResiduals = optimum.getResiduals().dotProduct(optimum.getResiduals());
r2 = 1 - ssResiduals / ssTotal;
adjustedR2 = getAdjustedCoefficientOfDetermination(ssResiduals, ssTotal, obs.length, parameters.length);
if (log) {
Utils.log(" Fit %d points. R^2 = %s. Adjusted R^2 = %s", obs.length, Utils.rounded(r2, 4), Utils.rounded(adjustedR2, 4));
Utils.log(" N=%s, nBlink=%s, tOff=%s (%s frames)", Utils.rounded(parameters[0], 4), Utils.rounded(parameters[1], 4), Utils.rounded(parameters[2], 4), Utils.rounded(parameters[2] / msPerFrame, 4));
}
return parameters;
} catch (TooManyIterationsException e) {
if (log)
Utils.log(" Failed to fit %d points: Too many iterations: (%s)", blinkingModel.size(), e.getMessage());
return null;
} catch (ConvergenceException e) {
if (log)
Utils.log(" Failed to fit %d points", blinkingModel.size());
return null;
}
}
use of org.apache.commons.math3.exception.ConvergenceException in project GDSC-SMLM by aherbert.
the class PCPALMFitting method fitRandomModel.
/**
* Fits the correlation curve with r>0 to the random 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 estimate protein density
* @return The fitted parameters [precision, density]
*/
private double[] fitRandomModel(double[][] gr, double sigmaS, double proteinDensity, String resultColour) {
final RandomModelFunction function = new RandomModelFunction();
randomModel = function;
log("Fitting %s: Estimated precision = %f nm, estimated protein density = %g um^-2", randomModel.getName(), sigmaS, proteinDensity * 1e6);
randomModel.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)
randomModel.addPoint(gr[0][i], gr[1][i]);
}
LevenbergMarquardtOptimizer optimizer = new LevenbergMarquardtOptimizer();
Optimum optimum;
try {
//@formatter:off
LeastSquaresProblem problem = new LeastSquaresBuilder().maxEvaluations(Integer.MAX_VALUE).maxIterations(3000).start(new double[] { sigmaS, proteinDensity }).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
optimum = optimizer.optimize(problem);
} catch (TooManyIterationsException e) {
log("Failed to fit %s: Too many iterations (%s)", randomModel.getName(), e.getMessage());
return null;
} catch (ConvergenceException e) {
log("Failed to fit %s: %s", randomModel.getName(), e.getMessage());
return null;
}
randomModel.setLogging(false);
double[] parameters = optimum.getPoint().toArray();
// Ensure the width is positive
parameters[0] = Math.abs(parameters[0]);
double ss = optimum.getResiduals().dotProduct(optimum.getResiduals());
ic1 = Maths.getAkaikeInformationCriterionFromResiduals(ss, randomModel.size(), parameters.length);
final double fitSigmaS = parameters[0];
final double fitProteinDensity = parameters[1];
// Check the fitted parameters are within tolerance of the initial estimates
double e1 = parameterDrift(sigmaS, fitSigmaS);
double e2 = parameterDrift(proteinDensity, fitProteinDensity);
log(" %s fit: SS = %f. cAIC = %f. %d evaluations", randomModel.getName(), ss, ic1, optimum.getEvaluations());
log(" %s parameters:", randomModel.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));
valid1 = 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%%)", randomModel.getName(), Utils.rounded(fittingTolerance, 4), fitSigmaS, Utils.rounded(e1, 4), fitProteinDensity * 1e6, Utils.rounded(e2, 4));
valid1 = false;
}
if (valid1) {
// ---------
// TODO - My data does not comply with this criteria.
// This could be due to the PC-PALM Molecule code limiting the nmPerPixel to fit the images in memory
// thus removing correlations at small r.
// It could also be due to the nature of the random simulations being 3D not 2D membranes
// as per the PC-PALM paper.
// ---------
// Evaluate g(r)protein where:
// g(r)peaks = g(r)protein + g(r)stoch
// g(r)peaks ~ 1 + g(r)stoch
// Verify g(r)protein should be <1.5 for all r>0
double[] gr_stoch = randomModel.value(parameters);
double[] gr_peaks = randomModel.getY();
double[] gr_ = randomModel.getX();
//SummaryStatistics stats = new SummaryStatistics();
for (int i = 0; i < gr_peaks.length; i++) {
// Only evaluate above the fitted average precision
if (gr_[i] < fitSigmaS)
continue;
// Note the RandomModelFunction evaluates g(r)stoch + 1;
double gr_protein_i = gr_peaks[i] - (gr_stoch[i] - 1);
if (gr_protein_i > gr_protein_threshold) {
// Failed fit
log(" Failed to fit %s: g(r)protein %s > %s @ r=%s", randomModel.getName(), Utils.rounded(gr_protein_i, 4), Utils.rounded(gr_protein_threshold, 4), Utils.rounded(gr_[i], 4));
valid1 = false;
}
//stats.addValue(gr_i);
//System.out.printf("g(r)protein @ %f = %f\n", gr[0][i], gr_protein_i);
}
}
addResult(randomModel.getName(), resultColour, valid1, fitSigmaS, fitProteinDensity, 0, 0, 0, 0, ic1);
return parameters;
}
Aggregations