R: Summarize columns of data.frame or task.

summarizeColumns {mlr} | R Documentation

## Summarize columns of data.frame or task.

### Description

Summarizes a data.frame, somewhat differently than the normal summary function of R. The function is mainly useful as a basic EDA tool on data.frames before they are converted to tasks, but can be used on tasks as well.

Columns can be of type numeric, integer, logical, factor, or character. Characters and logicals will be treated as factors.

### Usage

    summarizeColumns(obj)

### Arguments

`obj` | (data.frame | Task) Input data.

### Value

(data.frame). With columns:

`name` | Name of column.
`type` | Data type of column.
`na` | Number of NAs in column.
`disp` | Measure of dispersion, for numerics and integers sd is used, for categorical columns the qualitative variation.
`mean` | Mean value of column, NA for categorical columns.
`median` | Median value of column, NA for categorical columns.
`mad` | MAD of column, NA for categorical columns.
`min` | Minimal value of column, for categorical columns the size of the smallest category.
`max` | Maximal value of column, for categorical columns the size of the largest category.
`nlevs` | For categorical columns, the number of factor levels, NA else.

### See Also

Other eda_and_preprocess: `capLargeValues`, `createDummyFeatures`, `dropFeatures`, `mergeSmallFactorLevels`, `normalizeFeatures`, `removeConstantFeatures`, `summarizeLevels`

### Examples

    summarizeColumns(iris)

[Package mlr version 2.16.0 Index]