Danfo.js
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    • Input/Output
      • danfo.readExcel
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    • Series
      • Creating a Series
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    • Dataframe
      • Creating a DataFrame
      • DataFrame.sortIndex
      • DataFrame.append
      • DataFrame.nUnique
      • DataFrame.tensor
      • DataFrame.print
      • DataFrame.toCSV
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      • DataFrame.selectDtypes
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      • DataFrame.loc
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      • DataFrame.at
      • DataFrame.iat
      • DataFrame.head
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      • DataFrame.sample
      • DataFrame.add
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      • DataFrame.copy
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      • DataFrame.query
      • DataFrame.addColumn
      • DataFrame.groupby
      • DataFrame.column
      • DataFrame.fillNa
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      • DataFrame.apply
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      • DataFrame.It
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      • DataFrame.ge
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    • Configuration Options
    • Plotting
      • Timeseries Plots
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    • Groupby
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      • Groupby.count
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      • Groupby.cumProd
      • Groupby.agg
  • User Guides
    • Migrating to the stable version of Danfo.js
    • Using Danfojs in React
    • Titanic Survival Prediction using Danfo.js and Tensorflow.js
  • Building Data Driven Applications with Danfo.js - Book
  • Contributing Guide
  • Release Notes
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On this page
  • Examples
  • Computes the variance of values along default axis 1 (column)
  • Computes the variance of values along row axis (0)

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  1. API reference
  2. Dataframe

DataFrame.var

Return unbiased variance over requested axis.

danfo.DataFrame.var(options)

Parameters
Type
Description
Default

options

Object

axis: 0 or 1. If 0, compute the mean column-wise, if 1, row-wise. Defaults to 1

{ axis: 1 }

Examples

Computes the variance of values along default axis 1 (column)

const dfd = require("danfojs-node")

let data = [[11, 20, 3], [1, 15, 6], [2, 30, 40], [2, 89, 78]]
let cols = ["A", "B", "C"]

let df = new dfd.DataFrame(data, { columns: cols })
df.print()
df.var().print()
╔════════════╤═══════════════════╤═══════════════════╤═══════════════════╗
║            │ A                 │ B                 │ C                 ║
╟────────────┼───────────────────┼───────────────────┼───────────────────╢
║ 0          │ 11                │ 20                │ 3                 ║
╟────────────┼───────────────────┼───────────────────┼───────────────────╢
║ 1          │ 1                 │ 15                │ 6                 ║
╟────────────┼───────────────────┼───────────────────┼───────────────────╢
║ 2          │ 2                 │ 30                │ 40                ║
╟────────────┼───────────────────┼───────────────────┼───────────────────╢
║ 3          │ 2                 │ 89                │ 78                ║
╚════════════╧═══════════════════╧═══════════════════╧═══════════════════╝

╔═══╤═══════════════════╗
║ 0 │ 72.33333333333334 ║
╟───┼───────────────────╢
║ 1 │ 50.33333333333333 ║
╟───┼───────────────────╢
║ 2 │ 388               ║
╟───┼───────────────────╢
║ 3 │ 2244.333333333333 ║
╚═══╧═══════════════════╝

Computes the variance of values along row axis (0)

const dfd = require("danfojs-node")

let data = [[11, 20, 3], [1, 15, 6], [2, 30, 40], [2, 89, 78]]
let cols = ["A", "B", "C"]

let df = new dfd.DataFrame(data, { columns: cols })
df.print()
df.var({ axis: 0 }).print()
╔════════════╤═══════════════════╤═══════════════════╤═══════════════════╗
║            │ A                 │ B                 │ C                 ║
╟────────────┼───────────────────┼───────────────────┼───────────────────╢
║ 0          │ 11                │ 20                │ 3                 ║
╟────────────┼───────────────────┼───────────────────┼───────────────────╢
║ 1          │ 1                 │ 15                │ 6                 ║
╟────────────┼───────────────────┼───────────────────┼───────────────────╢
║ 2          │ 2                 │ 30                │ 40                ║
╟────────────┼───────────────────┼───────────────────┼───────────────────╢
║ 3          │ 2                 │ 89                │ 78                ║
╚════════════╧═══════════════════╧═══════════════════╧═══════════════════╝

╔═══╤════════════════════╗
║ A │ 22                 ║
╟───┼────────────────────╢
║ B │ 1172.3333333333333 ║
╟───┼────────────────────╢
║ C │ 1232.25            ║
╚═══╧════════════════════╝
PreviousDataFrame.stdNextDataFrame.count

Last updated 3 years ago

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