Default event Latent Model. More...
#include <ql/experimental/credit/defaultprobabilitylatentmodel.hpp>
Public Member Functions | |
DefaultLatentModel (const std::vector< std::vector< Real > > &factorWeights, LatentModelIntegrationType::LatentModelIntegrationType integralType, const initTraits &ini=initTraits()) | |
DefaultLatentModel (const Handle< Quote > &mktCorrel, Size nVariables, LatentModelIntegrationType::LatentModelIntegrationType integralType, const initTraits &ini=initTraits()) | |
void | resetBasket (const ext::shared_ptr< Basket > &basket) const |
Probability | conditionalDefaultProbability (Probability prob, Size iName, const std::vector< Real > &mktFactors) const |
Probability | conditionalDefaultProbabilityInvP (Real invCumYProb, Size iName, const std::vector< Real > &m) const |
Probability | probOfDefault (Size iName, const Date &d) const |
Real | defaultCorrelation (const Date &d, Size iNamei, Size iNamej) const |
Probability | probAtLeastNEvents (Size n, const Date &date) const |
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void | update () |
Size | size () const |
Size | numFactors () const |
Number of systemic factors. | |
Size | numTotalFactors () const |
Number of total free random factors; systemic and idiosyncratic. | |
LatentModel (const std::vector< std::vector< Real > > &factorsWeights, const typename copulaType::initTraits &ini=copulaType::initTraits()) | |
LatentModel (const std::vector< Real > &factorsWeight, const typename copulaType::initTraits &ini=copulaType::initTraits()) | |
LatentModel (Real correlSqr, Size nVariables, const typename copulaType::initTraits &ini=copulaType::initTraits()) | |
LatentModel (const Handle< Quote > &singleFactorCorrel, Size nVariables, const typename copulaType::initTraits &ini=copulaType::initTraits()) | |
const std::vector< std::vector< Real > > & | factorWeights () const |
Provides values of the factors \( a_{i,k} \). | |
const std::vector< Real > & | idiosyncFctrs () const |
Provides values of the normalized idiosyncratic factors \( Z_i \). | |
Real | latentVariableCorrel (Size iVar1, Size iVar2) const |
Latent variable correlations: | |
Probability | cumulativeY (Real val, Size iVariable) const |
Probability | cumulativeZ (Real z) const |
Cumulative distribution of Z, the idiosyncratic/error factors. | |
Probability | density (const std::vector< Real > &m) const |
Density function of M, the market/systemic factors. | |
Real | inverseCumulativeDensity (Probability p, Size iFactor) const |
Inverse cumulative distribution of the systemic factor iFactor. | |
Real | inverseCumulativeY (Probability p, Size iVariable) const |
Real | inverseCumulativeZ (Probability p) const |
Disposable< std::vector< Real > > | allFactorCumulInverter (const std::vector< Real > &probs) const |
Real | latentVarValue (const std::vector< Real > &allFactors, Size iVar) const |
const copulaType & | copula () const |
Real | integratedExpectedValue (const ext::function< Real(const std::vector< Real > &v1)> &f) const |
Disposable< std::vector< Real > > | integratedExpectedValue (const ext::function< Disposable< std::vector< Real > >(const std::vector< Real > &v1)> &f) const |
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Observer (const Observer &) | |
Observer & | operator= (const Observer &) |
std::pair< iterator, bool > | registerWith (const ext::shared_ptr< Observable > &) |
void | registerWithObservables (const ext::shared_ptr< Observer > &) |
Size | unregisterWith (const ext::shared_ptr< Observable > &) |
void | unregisterWithAll () |
virtual void | deepUpdate () |
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Observable (const Observable &) | |
Observable & | operator= (const Observable &) |
void | notifyObservers () |
Protected Member Functions | |
void | update () |
Probability | conditionalDefaultProbability (const Date &date, Size iName, const std::vector< Real > &mktFactors) const |
Probability | condProbProduct (Real invCumYProb1, Real invCumYProb2, Size iName1, Size iName2, const std::vector< Real > &mktFactors) const |
Real | conditionalProbAtLeastNEvents (Size n, const Date &date, const std::vector< Real > &mktFactors) const |
Conditional probability of n default events or more. | |
const ext::shared_ptr< LMIntegration > & | integration () const |
access to integration: | |
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virtual const ext::shared_ptr< LMIntegration > & | integration () const |
Protected Attributes | |
ext::shared_ptr< Basket > | basket_ |
ext::shared_ptr< LMIntegration > | integration_ |
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std::vector< std::vector< Real > > | factorWeights_ |
Handle< Quote > | cachedMktFactor_ |
std::vector< Real > | idiosyncFctrs_ |
Size | nFactors_ |
Number of systemic factors. | |
Size | nVariables_ |
Number of latent model variables, idiosyncratic terms or model dim. | |
copulaType | copula_ |
Additional Inherited Members | |
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typedef copulaPolicy | copulaType |
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typedef boost::unordered_set< ext::shared_ptr< Observable > > | set_type |
typedef set_type::iterator | iterator |
Default event Latent Model.
This is a model for joint default events based on a generic Latent Model. It models solely the default events in a portfolio, not making any reference to severities, exposures, etc... An implicit correspondence is stablished between the variables modelled and the names in the basket given by the basket and model variable access indices. The class is parametric on the Latent Model copula.
DefaultLatentModel | ( | const std::vector< std::vector< Real > > & | factorWeights, |
LatentModelIntegrationType::LatentModelIntegrationType | integralType, | ||
const initTraits & | ini = initTraits() |
||
) |
factorWeights | Latent model independent factors weights for each variable. |
integralType | Integration type. |
ini | Copula initialization if any. |
Probability conditionalDefaultProbability | ( | Probability | prob, |
Size | iName, | ||
const std::vector< Real > & | mktFactors | ||
) | const |
Returns the probability of default of a given name conditional on the realization of a given set of values of the model independent factors. The date at which the probability is given is implicit in the probability since theres not other time dependence in this model.
prob | Unconditional probability of default. |
iName | desired name. |
mktFactors | Value of LM independent factors. |
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protectedvirtual |
This method must be implemented in derived classes. An instance of Observer does not call this method directly: instead, it will be called by the observables the instance registered with when they need to notify any changes.
Implements Observer.
Probability conditionalDefaultProbabilityInvP | ( | Real | invCumYProb, |
Size | iName, | ||
const std::vector< Real > & | m | ||
) | const |
Returns the probability of default of a given name conditional on the realization of a given set of values of the model independent factors. The date at which the probability is given is implicit in the probability since theres not other time dependent in this model. Same intention as above but provides a performance opportunity, if the integration is along the market factors (as usually is) avoids computing the inverse of the probability on each call.
invCumYProb | Inverse cumul of the unconditional probability of default, has to follow the same copula law for results to be coherent |
iName | desired name. |
m | Value of LM independent factors. |
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protected |
Returns the probability of default of a given name conditional on the realization of a given set of values of the model independent factors.
date | The date for the probability of default. |
iName | desired name. |
mktFactors | Value of LM independent factors. |
Same intention as the above methods. Usage of this one is typically more expensive because most often the date we call this method with repeats itself and with this one the probability can not be cached outside the call.
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protected |
Conditional default probability product, intermediate step in the correlation calculation.
Probability probOfDefault | ( | Size | iName, |
const Date & | d | ||
) | const |
Computes the unconditional probability of default of a given name. Trivial method for testing
Pearsons' default probability correlation. Users should consider specialization on the copula type for specific distributions since that might simplify the integrations, most importantly if this is to be used in calibration of observations for factor coefficients as it is expensive to integrate directly.
Probability probAtLeastNEvents | ( | Size | n, |
const Date & | date | ||
) | const |
Returns the probaility of having a given or larger number of defaults in the basket portfolio at a given time.