Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Effect of Class Imbalance on Precision-Recall Curves   In this note I study how the precision of a classifier depends on the ratio
$r$ of positive to negative cases in the test set, as well as the classifier's
true and false positive rates. This relationship allows prediction of how the
precision-recall curve will change with $r$, which seems not to be well known.
It also allows prediction of how $F_{\beta}$ and the Precision Gain and Recall
Gain measures of Flach and Kull (2015) vary with $r$.

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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ex
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The categories of this paper are: math-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: nlin
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The categories of this paper are: quant-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex
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The categories of this paper are: mtrl-th