PHP Conference Nagoya 2025

SVM::crossvalidate

(PECL svm >= 0.1.0)

SVM::crossvalidateTest training params on subsets of the training data

Beschreibung

public svm::crossvalidate(array $problem, int $number_of_folds): float

Crossvalidate can be used to test the effectiveness of the current parameter set on a subset of the training data. Given a problem set and a n "folds", it separates the problem set into n subsets, and the repeatedly trains on one subset and tests on another. While the accuracy will generally be lower than a SVM trained on the enter data set, the accuracy score returned should be relatively useful, so it can be used to test different training parameters.

Parameter-Liste

problem

The problem data. This can either be in the form of an array, the URL of an SVMLight formatted file, or a stream to an opened SVMLight formatted datasource.

number_of_folds

The number of sets the data should be divided into and cross tested. A higher number means smaller training sets and less reliability. 5 is a good number to start with.

Rückgabewerte

The correct percentage, expressed as a floating point number from 0-1. In the case of NU_SVC or EPSILON_SVR kernels the mean squared error will returned instead.

Siehe auch

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User Contributed Notes 1 note

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kadirerturk at gmail dot com
10 years ago
$svm = new SVM();
$cross = $svm->crossvalidate("/svmScaled.data" , 5); // 5 fold cross val
var_dump($cross); //
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