Examples with MassActionKinetics cbit.vcell.model.MassActionKinetics used on opensource projects

Example 11 with MassActionKinetics

use of cbit.vcell.model.MassActionKinetics in project vcell by virtualcell.

the class ApplicationConstraintsGenerator method fromApplication.

/**
 * Insert the method's description here.
 * Creation date: (6/26/01 8:25:55 AM)
 * @return cbit.vcell.constraints.ConstraintContainerImpl
 */
public static ConstraintContainerImpl fromApplication(SimulationContext simContext) {
    try {
        ConstraintContainerImpl ccImpl = new ConstraintContainerImpl();
        // ====================
        // add physical limits
        // ====================
        // 
        // no negative concentrations
        // 
        cbit.vcell.model.Model model = simContext.getModel();
        cbit.vcell.model.SpeciesContext[] speciesContexts = model.getSpeciesContexts();
        for (int i = 0; i < speciesContexts.length; i++) {
            ccImpl.addSimpleBound(new SimpleBounds(speciesContexts[i].getName(), new RealInterval(0, Double.POSITIVE_INFINITY), AbstractConstraint.PHYSICAL_LIMIT, "non-negative concentration"));
        }
        for (int i = 0; i < speciesContexts.length; i++) {
            SpeciesContextSpecParameter initParam = (simContext.getReactionContext().getSpeciesContextSpec(speciesContexts[i])).getInitialConditionParameter();
            if (initParam != null) {
                double initialValue = initParam.getExpression().evaluateConstant();
                ccImpl.addSimpleBound(new SimpleBounds(speciesContexts[i].getName(), new RealInterval(initialValue), AbstractConstraint.MODELING_ASSUMPTION, "specified \"initialCondition\""));
            }
        }
        // =========================
        // add modeling assumptions
        // =========================
        // 
        // mass action forward and reverse rates should be non-negative
        // 
        cbit.vcell.model.ReactionStep[] reactionSteps = model.getReactionSteps();
        for (int i = 0; i < reactionSteps.length; i++) {
            Kinetics kinetics = reactionSteps[i].getKinetics();
            if (kinetics instanceof MassActionKinetics) {
                Expression forwardRateConstraintExp = new Expression(((MassActionKinetics) kinetics).getForwardRateParameter().getExpression().infix() + ">=0");
                forwardRateConstraintExp = getSteadyStateExpression(forwardRateConstraintExp);
                if (!forwardRateConstraintExp.compareEqual(new Expression(1.0))) {
                    ccImpl.addGeneralConstraint(new GeneralConstraint(forwardRateConstraintExp, AbstractConstraint.MODELING_ASSUMPTION, "non-negative forward rate"));
                }
                Expression reverseRateConstraintExp = new Expression(((MassActionKinetics) kinetics).getReverseRateParameter().getExpression().infix() + ">=0");
                reverseRateConstraintExp = getSteadyStateExpression(reverseRateConstraintExp);
                if (!reverseRateConstraintExp.compareEqual(new Expression(1.0))) {
                    ccImpl.addGeneralConstraint(new GeneralConstraint(reverseRateConstraintExp, AbstractConstraint.MODELING_ASSUMPTION, "non-negative reverse rate"));
                }
            }
            KineticsParameter authoritativeParameter = kinetics.getAuthoritativeParameter();
            Expression kineticRateConstraintExp = new Expression(authoritativeParameter.getName() + "==" + authoritativeParameter.getExpression().infix());
            kineticRateConstraintExp = getSteadyStateExpression(kineticRateConstraintExp);
            if (!kineticRateConstraintExp.compareEqual(new Expression(1.0))) {
                ccImpl.addGeneralConstraint(new GeneralConstraint(kineticRateConstraintExp, AbstractConstraint.MODELING_ASSUMPTION, "definition"));
            }
        }
        // 
        for (int i = 0; i < reactionSteps.length; i++) {
            Kinetics kinetics = reactionSteps[i].getKinetics();
            Kinetics.KineticsParameter[] parameters = kinetics.getKineticsParameters();
            for (int j = 0; j < parameters.length; j++) {
                Expression exp = parameters[j].getExpression();
                if (exp.getSymbols() == null || exp.getSymbols().length == 0) {
                    // 
                    try {
                        double constantValue = exp.evaluateConstant();
                        RealInterval interval = new RealInterval(constantValue);
                        ccImpl.addSimpleBound(new SimpleBounds(parameters[j].getName(), interval, AbstractConstraint.MODELING_ASSUMPTION, "model value"));
                    } catch (cbit.vcell.parser.ExpressionException e) {
                        System.out.println("error evaluating parameter " + parameters[j].getName() + " in reaction step " + reactionSteps[i].getName());
                    }
                } else {
                    Expression parameterDefinitionExp = new Expression(parameters[j].getName() + "==" + parameters[j].getExpression().infix());
                    parameterDefinitionExp = getSteadyStateExpression(parameterDefinitionExp);
                    if (!parameterDefinitionExp.compareEqual(new Expression(1.0))) {
                        ccImpl.addGeneralConstraint(new GeneralConstraint(parameterDefinitionExp, AbstractConstraint.MODELING_ASSUMPTION, "parameter definition"));
                    }
                }
            }
        }
        ccImpl.addSimpleBound(new SimpleBounds(model.getFARADAY_CONSTANT().getName(), new RealInterval(model.getFARADAY_CONSTANT().getExpression().evaluateConstant()), AbstractConstraint.PHYSICAL_LIMIT, "Faraday's constant"));
        ccImpl.addSimpleBound(new SimpleBounds(model.getTEMPERATURE().getName(), new RealInterval(300), AbstractConstraint.PHYSICAL_LIMIT, "Absolute Temperature Kelvin"));
        ccImpl.addSimpleBound(new SimpleBounds(model.getGAS_CONSTANT().getName(), new RealInterval(model.getGAS_CONSTANT().getExpression().evaluateConstant()), AbstractConstraint.PHYSICAL_LIMIT, "ideal gas constant"));
        ccImpl.addSimpleBound(new SimpleBounds(model.getKMILLIVOLTS().getName(), new RealInterval(model.getKMILLIVOLTS().getExpression().evaluateConstant()), AbstractConstraint.PHYSICAL_LIMIT, "ideal gas constant"));
        return ccImpl;
    } catch (cbit.vcell.parser.ExpressionException e) {
        e.printStackTrace(System.out);
        return null;
    } catch (java.beans.PropertyVetoException e) {
        e.printStackTrace(System.out);
        return null;
    }
}

Example 12 with MassActionKinetics

use of cbit.vcell.model.MassActionKinetics in project vcell by virtualcell.

the class BNGOutputPanel method getCollapsedReactionSteps.

private ReactionStep[] getCollapsedReactionSteps(ReactionStep[] reactionSteps) {
    Vector<ReactionStep> collapsedRxnStepsVector = new Vector<ReactionStep>();
    Vector<ReactionStep> rxnStepsVector = new Vector<ReactionStep>();
    for (int i = 0; i < reactionSteps.length; i++) {
        rxnStepsVector.addElement(reactionSteps[i]);
    }
    for (int i = 0; i < rxnStepsVector.size(); i++) {
        ReactionStep fwdRStep = rxnStepsVector.elementAt(i);
        // Get the reactionParticipants and the corresponding reactants and products in an array
        ReactionParticipant[] rps = fwdRStep.getReactionParticipants();
        Vector<SpeciesContext> fwdReactantsVector = new Vector<SpeciesContext>();
        Vector<SpeciesContext> fwdProductsVector = new Vector<SpeciesContext>();
        for (int j = 0; j < rps.length; j++) {
            if (rps[j] instanceof Reactant) {
                fwdReactantsVector.addElement(rps[j].getSpeciesContext());
            } else if (rps[j] instanceof Product) {
                fwdProductsVector.addElement(rps[j].getSpeciesContext());
            }
        }
        SpeciesContext[] fwdReactants = (SpeciesContext[]) BeanUtils.getArray(fwdReactantsVector, SpeciesContext.class);
        SpeciesContext[] fwdProducts = (SpeciesContext[]) BeanUtils.getArray(fwdProductsVector, SpeciesContext.class);
        boolean bReverseReactionFound = false;
        // Loop through all the reactions to find the corresponding reverse reaction
        for (int ii = 0; ii < reactionSteps.length; ii++) {
            ReactionStep revRStep = reactionSteps[ii];
            // Get the reactionParticipants and the corresponding reactants and products in an array
            ReactionParticipant[] revRps = revRStep.getReactionParticipants();
            Vector<SpeciesContext> revReactantsVector = new Vector<SpeciesContext>();
            Vector<SpeciesContext> revProductsVector = new Vector<SpeciesContext>();
            for (int j = 0; j < revRps.length; j++) {
                if (revRps[j] instanceof Reactant) {
                    revReactantsVector.addElement(revRps[j].getSpeciesContext());
                } else if (revRps[j] instanceof Product) {
                    revProductsVector.addElement(revRps[j].getSpeciesContext());
                }
            }
            SpeciesContext[] revReactants = (SpeciesContext[]) BeanUtils.getArray(revReactantsVector, SpeciesContext.class);
            SpeciesContext[] revProducts = (SpeciesContext[]) BeanUtils.getArray(revProductsVector, SpeciesContext.class);
            // Check if reactants of reaction in outer 'for' loop match products in inner 'for' loop and vice versa.
            if (BeanUtils.arrayEquals(fwdReactants, revProducts) && BeanUtils.arrayEquals(fwdProducts, revReactants)) {
                // Set the reverse kinetic rate expression for the reaction in outer loop with the forward rate from reactionStep in inner loop
                // inner 'for' loop
                MassActionKinetics revMAKinetics = (MassActionKinetics) revRStep.getKinetics();
                // outer 'for' loop
                MassActionKinetics fwdMAKinetics = (MassActionKinetics) fwdRStep.getKinetics();
                try {
                    fwdMAKinetics.setParameterValue(fwdMAKinetics.getReverseRateParameter(), revMAKinetics.getForwardRateParameter().getExpression());
                    Kinetics.KineticsParameter param = revMAKinetics.getKineticsParameter(revMAKinetics.getForwardRateParameter().getExpression().infix());
                    fwdMAKinetics.setParameterValue(param, param.getExpression());
                } catch (Exception e) {
                    e.printStackTrace(System.out);
                    throw new RuntimeException(e.getMessage());
                }
                // Add this to the collapsedRxnStepsVector
                collapsedRxnStepsVector.addElement(fwdRStep);
                rxnStepsVector.removeElement(revRStep);
                bReverseReactionFound = true;
                break;
            }
        }
        // Add it as is to the 'collapsedRxnStepsVector'
        if (!bReverseReactionFound) {
            collapsedRxnStepsVector.addElement(fwdRStep);
        }
    }
    // Convert the vector into an array of reactionSteps and return
    ReactionStep[] collapsedRxnSteps = (ReactionStep[]) BeanUtils.getArray(collapsedRxnStepsVector, ReactionStep.class);
    return collapsedRxnSteps;
}

Example 13 with MassActionKinetics

use of cbit.vcell.model.MassActionKinetics in project vcell by virtualcell.

the class XmlReader method getKinetics.

/**
 * This method returns a Kinetics object from a XML Element based on the value of the kinetics type attribute.
 * Creation date: (3/19/2001 4:42:04 PM)
 * @return cbit.vcell.model.Kinetics
 * @param param org.jdom.Element
 */
private Kinetics getKinetics(Element param, ReactionStep reaction, Model model) throws XmlParseException {
    VariableHash varHash = new VariableHash();
    addResevedSymbols(varHash, model);
    String type = param.getAttributeValue(XMLTags.KineticsTypeAttrTag);
    Kinetics newKinetics = null;
    try {
        if (type.equalsIgnoreCase(XMLTags.KineticsTypeGeneralKinetics)) {
            // create a general kinetics
            newKinetics = new GeneralKinetics(reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeGeneralCurrentKinetics)) {
            // Create GeneralCurrentKinetics
            newKinetics = new GeneralCurrentKinetics(reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeMassAction) && reaction instanceof SimpleReaction) {
            // create a Mass Action kinetics
            newKinetics = new MassActionKinetics((SimpleReaction) reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeNernst) && reaction instanceof FluxReaction) {
            // create NernstKinetics
            newKinetics = new NernstKinetics((FluxReaction) reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeGHK) && reaction instanceof FluxReaction) {
            // create GHKKinetics
            newKinetics = new GHKKinetics((FluxReaction) reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeHMM_Irr) && reaction instanceof SimpleReaction) {
            // create HMM_IrrKinetics
            newKinetics = new HMM_IRRKinetics((SimpleReaction) reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeHMM_Rev) && reaction instanceof SimpleReaction) {
            // create HMM_RevKinetics
            newKinetics = new HMM_REVKinetics((SimpleReaction) reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeGeneralTotal_oldname)) {
            // create GeneralTotalKinetics
            newKinetics = new GeneralLumpedKinetics(reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeGeneralLumped)) {
            // create GeneralLumpedKinetics
            newKinetics = new GeneralLumpedKinetics(reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeGeneralCurrentLumped)) {
            // create GeneralCurrentLumpedKinetics
            newKinetics = new GeneralCurrentLumpedKinetics(reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeGeneralPermeability) && reaction instanceof FluxReaction) {
            // create GeneralPermeabilityKinetics
            newKinetics = new GeneralPermeabilityKinetics((FluxReaction) reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeMacroscopic_Irr) && reaction instanceof SimpleReaction) {
            // create Macroscopic_IRRKinetics
            newKinetics = new Macroscopic_IRRKinetics((SimpleReaction) reaction);
        } else if (type.equalsIgnoreCase(XMLTags.KineticsTypeMicroscopic_Irr) && reaction instanceof SimpleReaction) {
            // create Microscopic_IRRKinetics
            newKinetics = new Microscopic_IRRKinetics((SimpleReaction) reaction);
        } else {
            throw new XmlParseException("Unknown kinetics type: " + type);
        }
    } catch (ExpressionException e) {
        e.printStackTrace();
        throw new XmlParseException("Error creating the kinetics for reaction: " + reaction.getName(), e);
    }
    try {
        // transaction begin flag ... yeah, this is a hack
        newKinetics.reading(true);
        // Read all of the parameters
        List<Element> list = param.getChildren(XMLTags.ParameterTag, vcNamespace);
        // add constants that may be used in kinetics.
        // VariableHash varHash = getVariablesHash();
        ArrayList<String> reserved = new ArrayList<String>();
        ReservedSymbol[] reservedSymbols = reaction.getModel().getReservedSymbols();
        for (ReservedSymbol rs : reservedSymbols) {
            reserved.add(rs.getName());
        }
        try {
            if (reaction.getStructure() instanceof Membrane) {
                Membrane membrane = (Membrane) reaction.getStructure();
                varHash.addVariable(new Constant(membrane.getMembraneVoltage().getName(), new Expression(0.0)));
                reserved.add(membrane.getMembraneVoltage().getName());
            }
            // 
            // add Reactants, Products, and Catalysts (ReactionParticipants)
            // 
            ReactionParticipant[] rp = reaction.getReactionParticipants();
            for (int i = 0; i < rp.length; i++) {
                varHash.addVariable(new Constant(rp[i].getName(), new Expression(0.0)));
            }
        } catch (MathException e) {
            e.printStackTrace(System.out);
            throw new XmlParseException("error reordering parameters according to dependencies: ", e);
        }
        // 
        for (Element xmlParam : list) {
            String paramName = unMangle(xmlParam.getAttributeValue(XMLTags.NameAttrTag));
            String role = xmlParam.getAttributeValue(XMLTags.ParamRoleAttrTag);
            String paramExpStr = xmlParam.getText();
            Expression paramExp = unMangleExpression(paramExpStr);
            try {
                if (varHash.getVariable(paramName) == null) {
                    varHash.addVariable(new Function(paramName, paramExp, null));
                } else {
                    if (reserved.contains(paramName)) {
                        varHash.removeVariable(paramName);
                        varHash.addVariable(new Function(paramName, paramExp, null));
                    }
                }
            } catch (MathException e) {
                e.printStackTrace(System.out);
                throw new XmlParseException("error reordering parameters according to dependencies: ", e);
            }
            Kinetics.KineticsParameter tempParam = null;
            if (!role.equals(XMLTags.ParamRoleUserDefinedTag)) {
                tempParam = newKinetics.getKineticsParameterFromRole(Kinetics.getParamRoleFromDefaultDesc(role));
            } else {
                continue;
            }
            // hack for bringing in General Total kinetics without breaking.
            if (tempParam == null && newKinetics instanceof GeneralLumpedKinetics) {
                if (role.equals(Kinetics.GTK_AssumedCompartmentSize_oldname) || role.equals(Kinetics.GTK_ReactionRate_oldname) || role.equals(Kinetics.GTK_CurrentDensity_oldname)) {
                    continue;
                } else if (role.equals(VCMODL.TotalRate_oldname)) {
                    tempParam = newKinetics.getKineticsParameterFromRole(Kinetics.ROLE_LumpedReactionRate);
                }
            }
            // hack from bringing in chargeValence parameters without breaking
            if (tempParam == null && Kinetics.getParamRoleFromDefaultDesc(role) == Kinetics.ROLE_ChargeValence) {
                tempParam = newKinetics.getChargeValenceParameter();
            }
            if (tempParam == null) {
                throw new XmlParseException("parameter with role '" + role + "' not found in kinetics type '" + type + "'");
            }
            // 
            if (!tempParam.getName().equals(paramName)) {
                Kinetics.KineticsParameter multNameParam = newKinetics.getKineticsParameter(paramName);
                int n = 0;
                while (multNameParam != null) {
                    String tempName = paramName + "_" + n++;
                    newKinetics.renameParameter(paramName, tempName);
                    multNameParam = newKinetics.getKineticsParameter(tempName);
                }
                newKinetics.renameParameter(tempParam.getName(), paramName);
            }
        }
        // 
        // create unresolved parameters for all unresolved symbols
        // 
        String unresolvedSymbol = varHash.getFirstUnresolvedSymbol();
        while (unresolvedSymbol != null) {
            try {
                // will turn into an UnresolvedParameter.
                varHash.addVariable(new Function(unresolvedSymbol, new Expression(0.0), null));
            } catch (MathException e) {
                e.printStackTrace(System.out);
                throw new XmlParseException(e);
            }
            newKinetics.addUnresolvedParameter(unresolvedSymbol);
            unresolvedSymbol = varHash.getFirstUnresolvedSymbol();
        }
        Variable[] sortedVariables = varHash.getTopologicallyReorderedVariables();
        ModelUnitSystem modelUnitSystem = reaction.getModel().getUnitSystem();
        for (int i = sortedVariables.length - 1; i >= 0; i--) {
            if (sortedVariables[i] instanceof Function) {
                Function paramFunction = (Function) sortedVariables[i];
                Element xmlParam = null;
                for (int j = 0; j < list.size(); j++) {
                    Element tempParam = (Element) list.get(j);
                    if (paramFunction.getName().equals(unMangle(tempParam.getAttributeValue(XMLTags.NameAttrTag)))) {
                        xmlParam = tempParam;
                        break;
                    }
                }
                if (xmlParam == null) {
                    // must have been an unresolved parameter
                    continue;
                }
                String symbol = xmlParam.getAttributeValue(XMLTags.VCUnitDefinitionAttrTag);
                VCUnitDefinition unit = null;
                if (symbol != null) {
                    unit = modelUnitSystem.getInstance(symbol);
                }
                Kinetics.KineticsParameter tempParam = newKinetics.getKineticsParameter(paramFunction.getName());
                if (tempParam == null) {
                    newKinetics.addUserDefinedKineticsParameter(paramFunction.getName(), paramFunction.getExpression(), unit);
                } else {
                    newKinetics.setParameterValue(tempParam, paramFunction.getExpression());
                    tempParam.setUnitDefinition(unit);
                }
            }
        }
    } catch (java.beans.PropertyVetoException e) {
        e.printStackTrace(System.out);
        throw new XmlParseException("Exception while setting parameters for Reaction : " + reaction.getName(), e);
    } catch (ExpressionException e) {
        e.printStackTrace(System.out);
        throw new XmlParseException("Exception while settings parameters for Reaction : " + reaction.getName(), e);
    } finally {
        newKinetics.reading(false);
    }
    return newKinetics;
}

Example 14 with MassActionKinetics

use of cbit.vcell.model.MassActionKinetics in project vcell by virtualcell.

the class ReactionPropertiesPanel method setReversible.

private void setReversible(boolean bReversible) {
    reactionStep.setReversible(bReversible);
    if (reactionStep.getKinetics() instanceof MassActionKinetics) {
        KineticsParameter kp = reactionStep.getKinetics().getKineticsParameterFromRole(Kinetics.ROLE_KReverse);
        kp.setExpression(new Expression(0.0d));
    }
    getParameterTableModel().refreshData();
}

Example 15 with MassActionKinetics

use of cbit.vcell.model.MassActionKinetics in project vcell by virtualcell.

the class FRAPStudy method createNewSimBioModel.

public static BioModel createNewSimBioModel(FRAPStudy sourceFrapStudy, Parameter[] params, TimeStep tStep, KeyValue simKey, User owner, int startingIndexForRecovery) throws Exception {
    if (owner == null) {
        throw new Exception("Owner is not defined");
    }
    ROI cellROI_2D = sourceFrapStudy.getFrapData().getRoi(FRAPData.VFRAP_ROI_ENUM.ROI_CELL.name());
    double df = params[FRAPModel.INDEX_PRIMARY_DIFF_RATE].getInitialGuess();
    double ff = params[FRAPModel.INDEX_PRIMARY_FRACTION].getInitialGuess();
    double bwmRate = params[FRAPModel.INDEX_BLEACH_MONITOR_RATE].getInitialGuess();
    double dc = 0;
    double fc = 0;
    double bs = 0;
    double onRate = 0;
    double offRate = 0;
    if (params.length == FRAPModel.NUM_MODEL_PARAMETERS_TWO_DIFF) {
        dc = params[FRAPModel.INDEX_SECONDARY_DIFF_RATE].getInitialGuess();
        fc = params[FRAPModel.INDEX_SECONDARY_FRACTION].getInitialGuess();
    } else if (params.length == FRAPModel.NUM_MODEL_PARAMETERS_BINDING) {
        dc = params[FRAPModel.INDEX_SECONDARY_DIFF_RATE].getInitialGuess();
        fc = params[FRAPModel.INDEX_SECONDARY_FRACTION].getInitialGuess();
        bs = params[FRAPModel.INDEX_BINDING_SITE_CONCENTRATION].getInitialGuess();
        onRate = params[FRAPModel.INDEX_ON_RATE].getInitialGuess();
        offRate = params[FRAPModel.INDEX_OFF_RATE].getInitialGuess();
    }
    // immobile fraction
    double fimm = 1 - ff - fc;
    if (fimm < FRAPOptimizationUtils.epsilon && fimm > (0 - FRAPOptimizationUtils.epsilon)) {
        fimm = 0;
    }
    if (fimm < (1 + FRAPOptimizationUtils.epsilon) && fimm > (1 - FRAPOptimizationUtils.epsilon)) {
        fimm = 1;
    }
    Extent extent = sourceFrapStudy.getFrapData().getImageDataset().getExtent();
    double[] timeStamps = sourceFrapStudy.getFrapData().getImageDataset().getImageTimeStamps();
    TimeBounds timeBounds = new TimeBounds(0.0, timeStamps[timeStamps.length - 1] - timeStamps[startingIndexForRecovery]);
    double timeStepVal = timeStamps[startingIndexForRecovery + 1] - timeStamps[startingIndexForRecovery];
    int numX = cellROI_2D.getRoiImages()[0].getNumX();
    int numY = cellROI_2D.getRoiImages()[0].getNumY();
    int numZ = cellROI_2D.getRoiImages().length;
    short[] shortPixels = cellROI_2D.getRoiImages()[0].getPixels();
    byte[] bytePixels = new byte[numX * numY * numZ];
    final byte EXTRACELLULAR_PIXVAL = 0;
    final byte CYTOSOL_PIXVAL = 1;
    for (int i = 0; i < bytePixels.length; i++) {
        if (shortPixels[i] != 0) {
            bytePixels[i] = CYTOSOL_PIXVAL;
        }
    }
    VCImage maskImage;
    try {
        maskImage = new VCImageUncompressed(null, bytePixels, extent, numX, numY, numZ);
    } catch (ImageException e) {
        e.printStackTrace();
        throw new RuntimeException("failed to create mask image for geometry");
    }
    Geometry geometry = new Geometry("geometry", maskImage);
    if (geometry.getGeometrySpec().getNumSubVolumes() != 2) {
        throw new Exception("Cell ROI has no ExtraCellular.");
    }
    int subVolume0PixVal = ((ImageSubVolume) geometry.getGeometrySpec().getSubVolume(0)).getPixelValue();
    geometry.getGeometrySpec().getSubVolume(0).setName((subVolume0PixVal == EXTRACELLULAR_PIXVAL ? EXTRACELLULAR_NAME : CYTOSOL_NAME));
    int subVolume1PixVal = ((ImageSubVolume) geometry.getGeometrySpec().getSubVolume(1)).getPixelValue();
    geometry.getGeometrySpec().getSubVolume(1).setName((subVolume1PixVal == CYTOSOL_PIXVAL ? CYTOSOL_NAME : EXTRACELLULAR_NAME));
    geometry.getGeometrySurfaceDescription().updateAll();
    BioModel bioModel = new BioModel(null);
    bioModel.setName("unnamed");
    Model model = new Model("model");
    bioModel.setModel(model);
    model.addFeature(EXTRACELLULAR_NAME);
    Feature extracellular = (Feature) model.getStructure(EXTRACELLULAR_NAME);
    model.addFeature(CYTOSOL_NAME);
    Feature cytosol = (Feature) model.getStructure(CYTOSOL_NAME);
    // Membrane mem = model.addMembrane(EXTRACELLULAR_CYTOSOL_MEM_NAME);
    // model.getStructureTopology().setInsideFeature(mem, cytosol);
    // model.getStructureTopology().setOutsideFeature(mem, extracellular);
    String roiDataName = FRAPStudy.ROI_EXTDATA_NAME;
    final int SPECIES_COUNT = 4;
    final int FREE_SPECIES_INDEX = 0;
    final int BS_SPECIES_INDEX = 1;
    final int COMPLEX_SPECIES_INDEX = 2;
    final int IMMOBILE_SPECIES_INDEX = 3;
    Expression[] diffusionConstants = null;
    Species[] species = null;
    SpeciesContext[] speciesContexts = null;
    Expression[] initialConditions = null;
    diffusionConstants = new Expression[SPECIES_COUNT];
    species = new Species[SPECIES_COUNT];
    speciesContexts = new SpeciesContext[SPECIES_COUNT];
    initialConditions = new Expression[SPECIES_COUNT];
    // total initial condition
    FieldFunctionArguments postBleach_first = new FieldFunctionArguments(roiDataName, "postbleach_first", new Expression(0), VariableType.VOLUME);
    FieldFunctionArguments prebleach_avg = new FieldFunctionArguments(roiDataName, "prebleach_avg", new Expression(0), VariableType.VOLUME);
    Expression expPostBleach_first = new Expression(postBleach_first.infix());
    Expression expPreBleach_avg = new Expression(prebleach_avg.infix());
    Expression totalIniCondition = Expression.div(expPostBleach_first, expPreBleach_avg);
    // Free Species
    diffusionConstants[FREE_SPECIES_INDEX] = new Expression(df);
    species[FREE_SPECIES_INDEX] = new Species(FRAPStudy.SPECIES_NAME_PREFIX_MOBILE, "Mobile bleachable species");
    speciesContexts[FREE_SPECIES_INDEX] = new SpeciesContext(null, species[FREE_SPECIES_INDEX].getCommonName(), species[FREE_SPECIES_INDEX], cytosol);
    initialConditions[FREE_SPECIES_INDEX] = Expression.mult(new Expression(ff), totalIniCondition);
    // Immobile Species (No diffusion)
    // Set very small diffusion rate on immobile to force evaluation as state variable (instead of FieldData function)
    // If left as a function errors occur because functions involving FieldData require a database connection
    final String IMMOBILE_DIFFUSION_KLUDGE = "1e-14";
    diffusionConstants[IMMOBILE_SPECIES_INDEX] = new Expression(IMMOBILE_DIFFUSION_KLUDGE);
    species[IMMOBILE_SPECIES_INDEX] = new Species(FRAPStudy.SPECIES_NAME_PREFIX_IMMOBILE, "Immobile bleachable species");
    speciesContexts[IMMOBILE_SPECIES_INDEX] = new SpeciesContext(null, species[IMMOBILE_SPECIES_INDEX].getCommonName(), species[IMMOBILE_SPECIES_INDEX], cytosol);
    initialConditions[IMMOBILE_SPECIES_INDEX] = Expression.mult(new Expression(fimm), totalIniCondition);
    // BS Species
    diffusionConstants[BS_SPECIES_INDEX] = new Expression(IMMOBILE_DIFFUSION_KLUDGE);
    species[BS_SPECIES_INDEX] = new Species(FRAPStudy.SPECIES_NAME_PREFIX_BINDING_SITE, "Binding Site species");
    speciesContexts[BS_SPECIES_INDEX] = new SpeciesContext(null, species[BS_SPECIES_INDEX].getCommonName(), species[BS_SPECIES_INDEX], cytosol);
    initialConditions[BS_SPECIES_INDEX] = Expression.mult(new Expression(bs), totalIniCondition);
    // Complex species
    diffusionConstants[COMPLEX_SPECIES_INDEX] = new Expression(dc);
    species[COMPLEX_SPECIES_INDEX] = new Species(FRAPStudy.SPECIES_NAME_PREFIX_SLOW_MOBILE, "Slower mobile bleachable species");
    speciesContexts[COMPLEX_SPECIES_INDEX] = new SpeciesContext(null, species[COMPLEX_SPECIES_INDEX].getCommonName(), species[COMPLEX_SPECIES_INDEX], cytosol);
    initialConditions[COMPLEX_SPECIES_INDEX] = Expression.mult(new Expression(fc), totalIniCondition);
    // add reactions to species if there is bleachWhileMonitoring rate.
    for (int i = 0; i < initialConditions.length; i++) {
        model.addSpecies(species[i]);
        model.addSpeciesContext(speciesContexts[i]);
        // reaction with BMW rate, which should not be applied to binding site
        if (!(species[i].getCommonName().equals(FRAPStudy.SPECIES_NAME_PREFIX_BINDING_SITE))) {
            SimpleReaction simpleReaction = new SimpleReaction(model, cytosol, speciesContexts[i].getName() + "_bleach", true);
            model.addReactionStep(simpleReaction);
            simpleReaction.addReactant(speciesContexts[i], 1);
            MassActionKinetics massActionKinetics = new MassActionKinetics(simpleReaction);
            simpleReaction.setKinetics(massActionKinetics);
            KineticsParameter kforward = massActionKinetics.getForwardRateParameter();
            simpleReaction.getKinetics().setParameterValue(kforward, new Expression(new Double(bwmRate)));
        }
    }
    // add the binding reaction: F + BS <-> C
    SimpleReaction simpleReaction2 = new SimpleReaction(model, cytosol, "reac_binding", true);
    model.addReactionStep(simpleReaction2);
    simpleReaction2.addReactant(speciesContexts[FREE_SPECIES_INDEX], 1);
    simpleReaction2.addReactant(speciesContexts[BS_SPECIES_INDEX], 1);
    simpleReaction2.addProduct(speciesContexts[COMPLEX_SPECIES_INDEX], 1);
    MassActionKinetics massActionKinetics = new MassActionKinetics(simpleReaction2);
    simpleReaction2.setKinetics(massActionKinetics);
    KineticsParameter kforward = massActionKinetics.getForwardRateParameter();
    KineticsParameter kreverse = massActionKinetics.getReverseRateParameter();
    simpleReaction2.getKinetics().setParameterValue(kforward, new Expression(new Double(onRate)));
    simpleReaction2.getKinetics().setParameterValue(kreverse, new Expression(new Double(offRate)));
    // create simulation context
    SimulationContext simContext = new SimulationContext(bioModel.getModel(), geometry);
    bioModel.addSimulationContext(simContext);
    FeatureMapping cytosolFeatureMapping = (FeatureMapping) simContext.getGeometryContext().getStructureMapping(cytosol);
    FeatureMapping extracellularFeatureMapping = (FeatureMapping) simContext.getGeometryContext().getStructureMapping(extracellular);
    // Membrane plasmaMembrane = model.getStructureTopology().getMembrane(cytosol, extracellular);
    // MembraneMapping plasmaMembraneMapping = (MembraneMapping)simContext.getGeometryContext().getStructureMapping(plasmaMembrane);
    SubVolume cytSubVolume = geometry.getGeometrySpec().getSubVolume(CYTOSOL_NAME);
    SubVolume exSubVolume = geometry.getGeometrySpec().getSubVolume(EXTRACELLULAR_NAME);
    SurfaceClass pmSurfaceClass = geometry.getGeometrySurfaceDescription().getSurfaceClass(exSubVolume, cytSubVolume);
    cytosolFeatureMapping.setGeometryClass(cytSubVolume);
    extracellularFeatureMapping.setGeometryClass(exSubVolume);
    // plasmaMembraneMapping.setGeometryClass(pmSurfaceClass);
    cytosolFeatureMapping.getUnitSizeParameter().setExpression(new Expression(1.0));
    extracellularFeatureMapping.getUnitSizeParameter().setExpression(new Expression(1.0));
    for (int i = 0; i < speciesContexts.length; i++) {
        SpeciesContextSpec scs = simContext.getReactionContext().getSpeciesContextSpec(speciesContexts[i]);
        scs.getInitialConditionParameter().setExpression(initialConditions[i]);
        scs.getDiffusionParameter().setExpression(diffusionConstants[i]);
    }
    MathMapping mathMapping = simContext.createNewMathMapping();
    MathDescription mathDesc = mathMapping.getMathDescription();
    // Add total fluorescence as function of mobile(optional: and slower mobile) and immobile fractions
    mathDesc.addVariable(new Function(FRAPStudy.SPECIES_NAME_PREFIX_COMBINED, new Expression(species[FREE_SPECIES_INDEX].getCommonName() + "+" + species[COMPLEX_SPECIES_INDEX].getCommonName() + "+" + species[IMMOBILE_SPECIES_INDEX].getCommonName()), null));
    simContext.setMathDescription(mathDesc);
    SimulationVersion simVersion = new SimulationVersion(simKey, "sim1", owner, new GroupAccessNone(), new KeyValue("0"), new BigDecimal(0), new Date(), VersionFlag.Current, "", null);
    Simulation newSimulation = new Simulation(simVersion, mathDesc);
    simContext.addSimulation(newSimulation);
    newSimulation.getSolverTaskDescription().setTimeBounds(timeBounds);
    newSimulation.getMeshSpecification().setSamplingSize(cellROI_2D.getISize());
    // newSimulation.getSolverTaskDescription().setTimeStep(timeStep); // Sundials doesn't need time step
    newSimulation.getSolverTaskDescription().setSolverDescription(SolverDescription.SundialsPDE);
    // use exp time step as output time spec
    newSimulation.getSolverTaskDescription().setOutputTimeSpec(new UniformOutputTimeSpec(timeStepVal));
    return bioModel;
}