43 lines
943 B
Markdown
43 lines
943 B
Markdown
# Tf-idf Transformer
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Tf–idf, short for term frequency–inverse document frequency, is a numerical statistic that is intended to reflect how important a word is to a document in a collection or corpus.
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### Constructor Parameters
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* $samples (array) - samples for fit tf-idf model
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```
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use Phpml\FeatureExtraction\TfIdfTransformer;
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$samples = [
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[1, 2, 4],
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[0, 2, 1]
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];
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$transformer = new TfIdfTransformer($samples);
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```
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### Transformation
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To transform a collection of text samples, use the `transform` method. Example:
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```
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use Phpml\FeatureExtraction\TfIdfTransformer;
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$samples = [
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[0 => 1, 1 => 1, 2 => 2, 3 => 1, 4 => 0, 5 => 0],
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[0 => 1, 1 => 1, 2 => 0, 3 => 0, 4 => 2, 5 => 3],
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];
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$transformer = new TfIdfTransformer($samples);
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$transformer->transform($samples);
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/*
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$samples = [
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[0 => 0, 1 => 0, 2 => 0.602, 3 => 0.301, 4 => 0, 5 => 0],
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[0 => 0, 1 => 0, 2 => 0, 3 => 0, 4 => 0.602, 5 => 0.903],
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];
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*/
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```
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