OpenMS

This class implements a pair finding algorithm for consensus features. More...
#include <OpenMS/ANALYSIS/MAPMATCHING/StablePairFinder.h>
Public Types  
typedef BaseGroupFinder  Base 
Base class. More...  
Public Types inherited from ProgressLogger  
enum  LogType { CMD , GUI , NONE } 
Possible log types. More...  
Public Member Functions  
StablePairFinder ()  
Constructor. More...  
~StablePairFinder () override  
Destructor. More...  
void  run (const std::vector< ConsensusMap > &input_maps, ConsensusMap &result_map) override 
Run the algorithm. More...  
Public Member Functions inherited from BaseGroupFinder  
BaseGroupFinder ()  
Default constructor. More...  
~BaseGroupFinder () override  
Destructor. More...  
Public Member Functions inherited from DefaultParamHandler  
DefaultParamHandler (const String &name)  
Constructor with name that is displayed in error messages. More...  
DefaultParamHandler (const DefaultParamHandler &rhs)  
Copy constructor. More...  
virtual  ~DefaultParamHandler () 
Destructor. More...  
DefaultParamHandler &  operator= (const DefaultParamHandler &rhs) 
Assignment operator. More...  
virtual bool  operator== (const DefaultParamHandler &rhs) const 
Equality operator. More...  
void  setParameters (const Param ¶m) 
Sets the parameters. More...  
const Param &  getParameters () const 
Nonmutable access to the parameters. More...  
const Param &  getDefaults () const 
Nonmutable access to the default parameters. More...  
const String &  getName () const 
Nonmutable access to the name. More...  
void  setName (const String &name) 
Mutable access to the name. More...  
const std::vector< String > &  getSubsections () const 
Nonmutable access to the registered subsections. More...  
Public Member Functions inherited from ProgressLogger  
ProgressLogger ()  
Constructor. More...  
virtual  ~ProgressLogger () 
Destructor. More...  
ProgressLogger (const ProgressLogger &other)  
Copy constructor. More...  
ProgressLogger &  operator= (const ProgressLogger &other) 
Assignment Operator. More...  
void  setLogType (LogType type) const 
Sets the progress log that should be used. The default type is NONE! More...  
LogType  getLogType () const 
Returns the type of progress log being used. More...  
void  setLogger (ProgressLoggerImpl *logger) 
Sets the logger to be used for progress logging. More...  
void  startProgress (SignedSize begin, SignedSize end, const String &label) const 
Initializes the progress display. More...  
void  setProgress (SignedSize value) const 
Sets the current progress. More...  
void  endProgress (UInt64 bytes_processed=0) const 
void  nextProgress () const 
increment progress by 1 (according to range beginend) More...  
Internal helper classes and enums  
enum  { RT = Peak2D::RT , MZ = Peak2D::MZ } 
double  second_nearest_gap_ 
The distance to the second nearest neighbors must be by this factor larger than the distance to the matched element itself. More...  
bool  use_IDs_ 
Only match if peptide IDs are compatible? More...  
void  updateMembers_ () override 
This method is used to update extra member variables at the end of the setParameters() method. More...  
bool  compatibleIDs_ (const ConsensusFeature &feat1, const ConsensusFeature &feat2) const 
Checks if the peptide IDs of two features are compatible. More...  
const AASequence &  getBestHitSequence_ (const PeptideIdentification &peptideIdentification) const 
Returns the highest scoring peptide hit in the the given peptide identification. More...  
Additional Inherited Members  
Static Public Member Functions inherited from DefaultParamHandler  
static void  writeParametersToMetaValues (const Param &write_this, MetaInfoInterface &write_here, const String &key_prefix="") 
Writes all parameters to meta values. More...  
Protected Member Functions inherited from BaseGroupFinder  
void  checkIds_ (const std::vector< ConsensusMap > &maps) const 
Checks if all file descriptions have disjoint map identifiers. More...  
Protected Member Functions inherited from DefaultParamHandler  
void  defaultsToParam_ () 
Updates the parameters after the defaults have been set in the constructor. More...  
Protected Attributes inherited from DefaultParamHandler  
Param  param_ 
Container for current parameters. More...  
Param  defaults_ 
Container for default parameters. This member should be filled in the constructor of derived classes! More...  
std::vector< String >  subsections_ 
Container for registered subsections. This member should be filled in the constructor of derived classes! More...  
String  error_name_ 
Name that is displayed in error messages during the parameter checking. More...  
bool  check_defaults_ 
If this member is set to false no checking if parameters in done;. More...  
bool  warn_empty_defaults_ 
If this member is set to false no warning is emitted when defaults are empty;. More...  
Protected Attributes inherited from ProgressLogger  
LogType  type_ 
time_t  last_invoke_ 
ProgressLoggerImpl *  current_logger_ 
Static Protected Attributes inherited from ProgressLogger  
static int  recursion_depth_ 
This class implements a pair finding algorithm for consensus features.
It offers a method to determine pairs across two consensus maps. The corresponding consensus features must be aligned, but may have small position deviations.
The distance measure is implemented in class FeatureDistance  see there for details.
Additional criteria for pairing
Depending on parameter use_identifications
, peptide identifications annotated to the features may have to be compatible (i.e. no annotation or the same annotation) for a pairing to occur.
Stability criterion: The distance to the nearest neighbor must be smaller than the distance to the secondnearest neighbor by a certain factor, see parameter second_nearest_gap
. There is a nontrivial relation between this parameter and the maximum allowed difference (in RT or m/z) of the distance measure: If second_nearest_gap
is greater than one, lowering max_difference
may in fact lead to more  rather than fewer  pairings, because it increases the distance difference between the nearest and the secondnearest neighbor, so that the constraint imposed by second_nearest_gap
may be fulfilled more often.
Quality calculation
The quality of a pairing is computed from the distance between the paired elements (nearest neighbors) and the distances to the secondnearest neighbors of both elements, according to the formula:
\[ q_{i,j} = \big( 1  d_{i,j} \big) \cdot \big( 1  \frac{g \cdot d_{i,j}}{d_{2,i}} \big) \cdot \big( 1  \frac{g \cdot d_{i,j}}{d_{2,j}} \big) \cdot \]
\( q_{i,j} \) is the quality of the pairing of elements i and j, \( d_{i,j} \) is the distance between the two, \( d_{2,i} \) and \(d_{2,j} \) are the distances to the secondnearest neighbors of i and j, respectively, and g is the factor defined by parameter second_nearest_gap
.
Note that by the definition of the distance measure, \( 0 \leq d_{i,j} \leq 1 \) if i and j are to form a pair. The criteria for pairing further require that \( g \cdot d_{i,j} \leq d_{2,i} \) and \( g \cdot d_{i,j} \leq d_{2,j} \). This ensures that the resulting quality is always between one (best) and zero (worst).
For the final quality q of the consensus feature produced by merging two paired elements (i and j), the existing quality values of the two elements are taken into account. The final quality is a weighted average of the existing qualities ( \( q_i \) and \( q_j \)) and the quality of the pairing ( \( q_{i,j} \), see above):
\[ q = \frac{q_{i,j} + (s_i  1) \cdot q_i + (s_j  1) \cdot q_j}{s_i + s_j  1} \]
The weighting factors \( s_i \) and \( s_j \) are the sizes (i.e. numbers of subelements) of the two consensus features i and j. That way, it is possible to link several feature maps to a growing consensus map in a stepwise fashion (as done by FeatureGroupingAlgorithmUnlabeled), and in the end obtain quality values that incorporate the qualities of all pairings that occurred during the generation of a consensus feature. Note that "missing" elements (if a consensus feature does not contain subfeatures from all input maps) are not punished in this definition of quality.
Parameters of this class are:Name  Type  Default  Restrictions  Description 

second_nearest_gap  float  2.0  min: 1.0  Only link features whose distance to the second nearest neighbors (for both sides) is larger by 'second_nearest_gap' than the distance between the matched pair itself. 
use_identifications  string  false  true, false  Never link features that are annotated with different peptides (features without ID's always match; only the best hit per peptide identification is considered). 
ignore_charge  string  false  true, false  false [default]: pairing requires equal charge state (or at least one unknown charge '0'); true: Pairing irrespective of charge state 
ignore_adduct  string  true  true, false  true [default]: pairing requires equal adducts (or at least one without adduct annotation); true: Pairing irrespective of adducts 
distance_RT:max_difference  float  100.0  min: 0.0  Never pair features with a larger RT distance (in seconds). 
distance_RT:exponent  float  1.0  min: 0.0  Normalized RT differences ([01], relative to 'max_difference') are raised to this power (using 1 or 2 will be fast, everything else is REALLY slow) 
distance_RT:weight  float  1.0  min: 0.0  Final RT distances are weighted by this factor 
distance_MZ:max_difference  float  0.3  min: 0.0  Never pair features with larger m/z distance (unit defined by 'unit') 
distance_MZ:unit  string  Da  Da, ppm  Unit of the 'max_difference' parameter 
distance_MZ:exponent  float  2.0  min: 0.0  Normalized ([01], relative to 'max_difference') m/z differences are raised to this power (using 1 or 2 will be fast, everything else is REALLY slow) 
distance_MZ:weight  float  1.0  min: 0.0  Final m/z distances are weighted by this factor 
distance_intensity:exponent  float  1.0  min: 0.0  Differences in relative intensity ([01]) are raised to this power (using 1 or 2 will be fast, everything else is REALLY slow) 
distance_intensity:weight  float  0.0  min: 0.0  Final intensity distances are weighted by this factor 
distance_intensity:log_transform  string  disabled  enabled, disabled  Logtransform intensities? If disabled, d = int_f2  int_f1 / int_max. If enabled, d = log(int_f2 + 1)  log(int_f1 + 1) / log(int_max + 1)) 
typedef BaseGroupFinder Base 
Base class.
StablePairFinder  (  ) 
Constructor.

inlineoverride 
Destructor.

protected 
Checks if the peptide IDs of two features are compatible.
A feature without identification is always compatible. Otherwise, two features are compatible if the best peptide hits of their identifications have the same sequences.

protected 
Returns the highest scoring peptide hit in the the given peptide identification.
peptideIdentification  The peptideIdentification to scan. 

overridevirtual 
Run the algorithm.
Exception::IllegalArgument  is thrown if the input data is not valid. 
Implements BaseGroupFinder.

overrideprotectedvirtual 
This method is used to update extra member variables at the end of the setParameters() method.
Also call it at the end of the derived classes' copy constructor and assignment operator.
The default implementation is empty.
Reimplemented from DefaultParamHandler.

protected 
The distance to the second nearest neighbors must be by this factor larger than the distance to the matched element itself.

protected 
Only match if peptide IDs are compatible?