Classifiers, table of contents
Chapter 13.5: Naive bayes classifier
This section describes naive Bayes density estimation and classification.
- 13.5.1. Introduction
13.5.1. Introduction ↩
Naive Bayes classifier is implemented by the sdnbayes
function. For each
feature, it estimates a class-conditional distribution using a
histogram. Assuming independence of features, the per-class output is
computed as a product of per-feature class conditional densities.
By default, sdnbayes
uses histograms with 20 bins:
>> a
3000 by 2 sddata, 3 classes: 'apple'(1000) 'banana'(1000) 'stone'(1000)
>> p=sdnbayes
(a)
sequential pipeline 2x1 'naive Bayes+Decision'
1 naive Bayes 2x3
2 Decision 3x1 weighting, 3 classes
>> sdscatter
(a,p)
The number of histogram bins may be fixed manually with the second parameter (or 'bins' option):
>> p=sdnbayes
(a,50)
sequential pipeline 2x1 'naive Bayes+Decision'
1 naive Bayes 2x3
2 Decision 3x1 weighting, 3 classes