RealMassDecomposer Class Reference

Decomposes a real-valued mass over a real-valued alphabet of Weights, within a configurable absolute mass error. More...

#include <OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/RealMassDecomposer.h>

Collaboration diagram for RealMassDecomposer:

Public Types
typedef IntegerMassDecomposer	integer_decomposer_type
	Underlying integer decomposer.
typedef integer_decomposer_type::value_type	integer_value_type
	Integer mass values consumed by the integer decomposer.
typedef integer_decomposer_type::decompositions_type	decompositions_type
	Result type of the integer decomposer (collection of decompositions).
typedef unsigned long long	number_of_decompositions_type
	Counter type returned by getNumberOfDecompositions.
typedef std::map< unsigned int, std::pair< unsigned int, unsigned int > >	constraints_type
	Per-alphabet-entry count constraint: alphabet index -> (min count, max count); both bounds inclusive.

Public Member Functions
	RealMassDecomposer (const Weights &weights)
	Construct from an alphabet of Weights.
decompositions_type	getDecompositions (double mass, double error)
	All decompositions of mass within absolute tolerance error.
decompositions_type	getDecompositions (double mass, double error, const constraints_type &constraints)
	Same as getDecompositions(double,double), additionally filtered by per-alphabet count bounds.
number_of_decompositions_type	getNumberOfDecompositions (double mass, double error)
	Count of decompositions of mass within absolute tolerance error.

Private Attributes
Weights	weights_
	Alphabet captured at construction time.
std::pair< double, double >	rounding_errors_
	Minimum and maximum relative rounding errors of weights_, captured at construction time.
double	precision_
	Precision of weights_, captured at construction time.
std::shared_ptr< integer_decomposer_type >	decomposer_
	Lazy integer decomposer reused across calls; captured at construction time.

Detailed Description

Decomposes a real-valued mass over a real-valued alphabet of Weights, within a configurable absolute mass error.

Translates the real-valued problem into integer mass decomposition against the Weights' scaled integer alphabet: it computes the integer-mass window that brackets the user-supplied [mass - error, mass + error] range (accounting for the precision-induced rounding errors stored on Weights), runs an IntegerMassDecomposer over each integer mass in the window, then drops every integer decomposition whose reconstructed real parent mass still differs from mass by more than error.

Member Typedef Documentation

constraints_type

typedef std::map<unsigned int, std::pair<unsigned int, unsigned int> > constraints_type

Per-alphabet-entry count constraint: alphabet index -> (min count, max count); both bounds inclusive.

decompositions_type

typedef integer_decomposer_type::decompositions_type decompositions_type

Result type of the integer decomposer (collection of decompositions).

integer_decomposer_type

typedef IntegerMassDecomposer integer_decomposer_type

Underlying integer decomposer.

integer_value_type

typedef integer_decomposer_type::value_type integer_value_type

Integer mass values consumed by the integer decomposer.

number_of_decompositions_type

typedef unsigned long long number_of_decompositions_type

Counter type returned by getNumberOfDecompositions.

Constructor & Destructor Documentation

RealMassDecomposer()

RealMassDecomposer ( const Weights &  weights )

explicit

Construct from an alphabet of Weights.

The alphabet's precision and rounding-error bounds are captured at construction time and reused on every subsequent getDecompositions / getNumberOfDecompositions call.

Parameters

[in]

weights

Real-valued alphabet to decompose against.

Member Function Documentation

getDecompositions() [1/2]

decompositions_type getDecompositions	(	double	mass,
		double	error
	)

All decompositions of mass within absolute tolerance error.

Returns every alphabet-multiplicity vector whose reconstructed parent mass lies in [mass - error, mass + error].

Parameters

[in]	mass	Target real-valued mass.
[in]	error	Absolute mass tolerance.

Returns

Decompositions whose reconstructed real parent mass is within error of mass.

getDecompositions() [2/2]

decompositions_type getDecompositions	(	double	mass,
		double	error,
		const constraints_type &	constraints
	)

Same as getDecompositions(double,double), additionally filtered by per-alphabet count bounds.

For each entry (idx, (lo, hi)) in constraints, only decompositions d with lo <= d[idx] <= hi are kept. Constraints whose alphabet index does not appear in decompositions are simply skipped.

Parameters

[in]	mass	Target real-valued mass.
[in]	error	Absolute mass tolerance.
[in]	constraints	Per-alphabet-entry count bounds.

Returns

Decompositions that satisfy both the mass tolerance and every supplied count constraint.

getNumberOfDecompositions()

number_of_decompositions_type getNumberOfDecompositions	(	double	mass,
		double	error
	)

Count of decompositions of mass within absolute tolerance error.

Equivalent in result to getDecompositions(mass, error).size() but does not materialise the individual decompositions.

When mass - error is non-positive, the integer-mass window starts at 1 rather than at a non-positive value.

Parameters

[in]	mass	Target real-valued mass.
[in]	error	Absolute mass tolerance.

Returns

Number of decompositions whose reconstructed real parent mass is within error of mass.

Member Data Documentation

decomposer_

std::shared_ptr<integer_decomposer_type> decomposer_

private

Lazy integer decomposer reused across calls; captured at construction time.

precision_

double precision_

private

Precision of weights_, captured at construction time.

rounding_errors_

std::pair<double, double> rounding_errors_

private

Minimum and maximum relative rounding errors of weights_, captured at construction time.

weights_

Weights weights_

private

Alphabet captured at construction time.