casa
5.7.016

Class to deal with Levensthein distance of strings. More...
#include <StringDistance.h>
Public Member Functions  
StringDistance ()  
Default constructor sets maxDistance to 0. More...  
StringDistance (const String &source, Int maxDistance=1, Bool countSwaps=True, Bool ignoreBlanks=True, Bool caseInsensitive=False)  
Construct from the source string and maximum distance. More...  
const string &  source () const 
Get data members. More...  
Int  maxDistance () const 
const Matrix< Int > &  matrix () const 
Bool  match (const String &target) const 
Test if the given target string is within the maximum distance. More...  
Int  distance (const String &target) const 
Calculate the distance from the string to the string given in the constructor. More...  
Static Public Member Functions  
static Int  distance (const String &source, const String &target, Bool countSwaps=True) 
Calculate the distance between the two strings. More...  
static String  removeBlanks (const String &source) 
Remove blanks from the given string. More...  
Static Private Member Functions  
static Int  doDistance (const String &source, const String &target, Bool countSwaps, Matrix< Int > &matrix) 
Calculate the distance. More...  
Private Attributes  
String  itsSource 
Matrix< Int >  itsMatrix 
Int  itsMaxDistance 
Bool  itsCountSwaps 
Bool  itsIgnoreBlanks 
Bool  itsCaseInsensitive 
Class to deal with Levensthein distance of strings.
The Levenshtein Distance is a metric telling how similar strings are. It is also known as the Edit Distance.
The distance tells how many operations (i.e., character substitutions, insertions, and deletions are needed to transform one string into another.
There are several extensions to the basic definition:
This class optionally uses the swap extension. Furthermore one can optionally ignore blanks. By default both options are used.
The code is based on code written by Anders Sewerin Johansen. Calculating the distance is an expensive O(N^2) operation, thus should be used with care.
The class is constructed with the source string to compare against. Thereafter its match
or distance
function can be used for each target string.
Definition at line 69 of file StringDistance.h.
casacore::StringDistance::StringDistance  (  ) 
Default constructor sets maxDistance to 0.

explicit 
Construct from the source string and maximum distance.
If the maximum distance is negative, it defaults to 1+strlength/3. Note that maximum distance 0 means that the strings must match exactly.
Calculate the distance from the string to the string given in the constructor.
If the length of target exceeds source length + maxDistance, the difference in lengths is returned.

static 
Calculate the distance between the two strings.
This is slower than the distance
member function, because it has to allocate the underlying Matrix for each invocation.

staticprivate 
Calculate the distance.
Test if the given target string is within the maximum distance.
Referenced by casacore::TaqlRegex::match().
Definition at line 88 of file StringDistance.h.
References itsMatrix.

inline 
Definition at line 86 of file StringDistance.h.
References itsMaxDistance.
Remove blanks from the given string.

inline 

private 
Definition at line 121 of file StringDistance.h.

private 
Definition at line 119 of file StringDistance.h.

private 
Definition at line 120 of file StringDistance.h.
Definition at line 117 of file StringDistance.h.
Referenced by matrix().

private 
Definition at line 118 of file StringDistance.h.
Referenced by maxDistance().

private 
Definition at line 116 of file StringDistance.h.
Referenced by source().