# scale_mfd: Standardize Multivariate Functional Data. In funcharts: Functional Control Charts

## Description

Scale multivariate functional data contained in an object of class `mfd` by subtracting the mean function and dividing by the standard deviation function.

## Usage

 `1` ```scale_mfd(mfdobj, center = TRUE, scale = TRUE) ```

## Arguments

 `mfdobj` A multivariate functional data object of class `mfd`. `center` A logical value, or a `fd` object. When providing a logical value, if TRUE, `mfdobj` is centered, i.e. the functional mean function is calculated and subtracted from all observations in `mfdobj`, if FALSE, `mfdobj` is not centered. If `center` is a `fd` object, then this function is used as functional mean for centering. `scale` A logical value, or a `fd` object. When providing a logical value, if TRUE, `mfdobj` is scaled after possible centering, i.e. the functional standard deviation is calculated from all functional observations in `mfdobj` and then the observations are divided by this calculated standard deviation, if FALSE, `mfdobj` is not scaled. If `scale` is a `fd` object, then this function is used as standard deviation function for scaling.

## Details

This function has been written to work similarly as the function `scale` for matrices. When calculated, attributes `center` and `scale` are of class `fd` and have the same structure you get when you use `fda::mean.fd` and `fda::sd.fd`.

## Value

A standardized object of class `mfd`, with two attributes, if calculated, `center` and `scale`, storing the mean and standard deviation functions used for standardization.

## Examples

 ```1 2 3``` ```library(funcharts) mfdobj <- data_sim_mfd() mfdobj_scaled <- scale_mfd(mfdobj) ```

funcharts documentation built on March 15, 2021, 5:07 p.m.