Class: BayesClassifier

• Inheritance
• Description
• Instance protocol
  • text handling
• Examples

Inheritance:

   Object
   |
   +--TextClassifier
      |
      +--BayesClassifier

Package:

stx:libbasic2

Category:

Collections-Text-Support

Version:

rev: 1.5 date: 2021/01/20 15:39:45

user: cg

file: BayesClassifier.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

an initial experiment in bayes text classification.
see BayesClassifierTest
This is possibly unfinished and may need more work.

copyright
COPYRIGHT (c) 2016 by eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.

Instance protocol:

 classify: string

assume that it is a regular text.
split first into lines...

 classify: string asCategory: categoryName

 tokenProbabilityOf: token inCategory: category

Calculate probability that a `token` belongs to a `category`

Examples:

|b|

b := BayesClassifier new.
'teach it positive phrases'.
b classify:'amazing, awesome movie!! Yeah!!' asCategory: 'positive'.
b classify:'Sweet, this is incredibly, amazing, perfect, great!!' asCategory: 'positive'.

'teach it a negative phrase'.
b classify:'terrible, shitty thing. Damn. Sucks!!' asCategory: 'negative'.

'teach it a neutral phrase'.
b classify:'I dont really know what to make of this.' asCategory: 'neutral'.

'now test it to see that it correctly categorizes a new document'.
self assert:(b classify:'awesome, cool, amazing!! Yay.')= 'positive'.