# group: Some summary statistics of a vector for each level of a... In Rfast: A Collection of Efficient and Extremely Fast R Functions

## Description

Some summary statistics of a vector for each level of a grouping variable.

## Usage

 ```1 2 3 4``` ```group(x,ina,method="sum",ina.min=NULL,ina.max = NULL, ina.length.unique=NULL,mad.method="median") group.sum(x, ina,ina.max = NULL,ina.min = NULL) group.mean(x, ina,ina.max = max(ina)) ```

## Arguments

 `x` A numerical vector with data. `ina` A numerical vector with numbers. Note that zero and negative values are not allowed as this can cause R to run forever or crash. `ina.length.unique` Length of the unique numerical values of ina argument. `method` A character vector with values "sum", "var", "all", "any", "mad", "mean", "med", "min", "max", "min.max". `ina.max` Maximum number for vector ina. `ina.min` Minimum number for vector ina. `mad.method` A character vector with values "median", for median absolute deviation or "mean", for mean absolute deviation. This works only with method="mad".

## Details

This command works only for vectors. Median absolute deviation, mean, median, minimum, maximum are some of the options offered.

## Value

A vector with the variance, or standard deviation, or mean, or minimum, or maximum, or median, or minimum-maximum of x for each distinct value of ina.

## Author(s)

``` colmeans, colVars, colMedians ```
 ```1 2 3 4 5 6 7``` ```## Not run: x <- rgamma(100,1, 4) ina <- sample(1:5, 100, TRUE) res<-group(x, ina,method="var") ## End(Not run) ```