Chi2

`Chi2()` computes the basic \(\chi^2\) kernel for bag-of-words (BoW) or bag-of-visual-words
data. This kernel computes the similarity between two nonnegative vectors that represent
the occurrence counts of words in two different documents.

Kernel functions for diverse types of data (including, but not
restricted to: nonnegative and real vectors, real matrices, categorical
and ordinal variables, sets, strings), plus other utilities like kernel
similarity, kernel Principal Components Analysis (PCA) and features'
importance for Support Vector Machines (SVMs), which expand other 'R'
packages like 'kernlab'.

Elies Ramon

kerntools

Kernel Functions and Tools for Machine Learning Applications

Chi2 function

<dl><dt>X</dt>
<dd>Matrix or data.frame (dimension NxD) that contains nonnegative numbers. Each row represents
the counts of words of N documents, while each column is a word.</dd>
<dt>g</dt>
<dd>Gamma hyperparameter. If g=0 or NULL, `Chi2()` returns the LeCam
distances between the documents instead of the \(\chi^2\) kernel matrix.
(Defaults=NULL).</dd></dl>

Arguments

Chi-squared kernel — Chi2

<dl>

<dt>X</dt>
<dd>Matrix or data.frame (dimension NxD) that contains nonnegative numbers. Each row represents
the counts of words of N documents, while each column is a word.</dd>


<dt>g</dt>
<dd>Gamma hyperparameter. If g=0 or NULL, `Chi2()` returns the LeCam
distances between the documents instead of the \(\chi^2\) kernel matrix.
(Defaults=NULL).</dd>

</dl>

Chi2: Chi-squared kernel

Description

Usage

Value

Arguments

References

Examples