danfo.LabelEncoder
Encode target labels with value between 0 and n_classes-1.
danfo.js provides the LabelEncoder class for encoding Series and Arrays to integer between 0 and n_classes -1. This is mostly used as a preprocessing step before most machine learning tasks.
Examples
Label Encode values in a Series
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let data = ["dog","cat","man","dog","cat","man","man","cat"]
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let series = new dfd.Series(data)
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let encode = new dfd.LabelEncoder()
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encode.fit(series)
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console.log(encode);
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let sf_enc = encode.transform(series.values)
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sf_enc.print()
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let new_sf = encode.transform(["dog","man"])
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new_sf.print()
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Output
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LabelEncoder { label: [ 'dog', 'cat', 'man' ] }
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╔═══╤══════════════════════╗
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║ │ 0 ║
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╟───┼──────────────────────╢
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║ 0 │ 0 ║
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╟───┼──────────────────────╢
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║ 1 │ 1 ║
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╟───┼──────────────────────╢
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║ 2 │ 2 ║
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╟───┼──────────────────────╢
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║ 3 │ 0 ║
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╟───┼──────────────────────╢
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║ 4 │ 1 ║
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╟───┼──────────────────────╢
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║ 5 │ 2 ║
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╟───┼──────────────────────╢
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║ 6 │ 2 ║
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╟───┼──────────────────────╢
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║ 7 │ 1 ║
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╚═══╧══════════════════════╝
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╔═══╤══════════════════════╗
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║ │ 0 ║
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╟───┼──────────────────────╢
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║ 0 │ 0 ║
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╟───┼──────────────────────╢
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║ 1 │ 2 ║
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╚═══╧══════════════════════╝
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Labels not found in the original data used for fitting are represented with -1
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const dfd = require("danfojs-node")
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let data = { fruits: ['pear', 'mango', "pawpaw", "mango", "bean"] ,
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Count: [20, 30, 89, 12, 30],
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Country: ["NG", "NG", "GH", "RU", "RU"]}
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let df = new dfd.DataFrame(data)
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let encode = new dfd.LabelEncoder()
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encode.fit(df['fruits'])
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console.log(encode);
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let sf_enc = encode.transform(df['fruits'].values)
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sf_enc.print()
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let new_sf = encode.transform(["mango","man"])
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new_sf.print()
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Output
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LabelEncoder { label: [ 'pear', 'mango', 'pawpaw', 'bean' ] }
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╔═══╤══════════════════════╗
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║ │ 0 ║
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╟───┼──────────────────────╢
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║ 0 │ 0 ║
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╟───┼──────────────────────╢
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║ 1 │ 1 ║
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╟───┼──────────────────────╢
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║ 2 │ 2 ║
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╟───┼──────────────────────╢
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║ 3 │ 1 ║
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╟───┼──────────────────────╢
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║ 4 │ 3 ║
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╚═══╧══════════════════════╝
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╔═══╤══════════════════════╗
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║ │ 0 ║
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╟───┼──────────────────────╢
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║ 0 │ 1 ║
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╟───┼──────────────────────╢
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║ 1 │ -1 ║
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╚═══╧══════════════════════╝
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Last modified 1yr ago
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