# big_scale: Some scaling functions In bigstatsr: Statistical Tools for Filebacked Big Matrices

## Description

Some scaling functions for a Filebacked Big Matrix to be used as the `fun.scaling` parameter of some functions of this package.

## Usage

 `1` ```big_scale(center = TRUE, scale = TRUE) ```

## Arguments

 `center` A logical value: whether to return means or 0s. `scale` A logical value: whether to return standard deviations or 1s. You can't use scale without using center.

## Details

One could think about less common scalings, such as for example the "y-aware" scaling which uses the inverse of betas of column-wise linear regression as scaling. See this post for details. It would be easy to implement it using `big_colstats` to get column means and `big_univLinReg` to get betas (and then inverse them).

## Value

A new function that returns a data.frame of two vectors "center" and "scale" which are of the length of `ind.col`.

scale

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14``` ```X <- big_attachExtdata() # No scaling big_noscale <- big_scale(center = FALSE, scale = FALSE) class(big_noscale) # big_scale returns a new function str(big_noscale(X)) big_noscale2 <- big_scale(center = FALSE) str(big_noscale2(X)) # you can't scale without centering # Centering big_center <- big_scale(scale = FALSE) str(big_center(X)) # + scaling str(big_scale()(X)) ```

### Example output

```sh: 1: wc: Permission denied
sh: 1: cannot create /dev/null: Permission denied
[1] "function"
'data.frame':	4542 obs. of  2 variables:
\$ center: num  0 0 0 0 0 0 0 0 0 0 ...
\$ scale : num  1 1 1 1 1 1 1 1 1 1 ...
'data.frame':	4542 obs. of  2 variables:
\$ center: num  0 0 0 0 0 0 0 0 0 0 ...
\$ scale : num  1 1 1 1 1 1 1 1 1 1 ...
'data.frame':	4542 obs. of  2 variables:
\$ center: num  1.32 1.59 1.53 1.63 1.09 ...
\$ scale : num  1 1 1 1 1 1 1 1 1 1 ...
'data.frame':	4542 obs. of  2 variables:
\$ center: num  1.32 1.59 1.53 1.63 1.09 ...
\$ scale : num  0.679 0.569 0.627 0.558 0.719 ...
```

bigstatsr documentation built on April 5, 2021, 5:08 p.m.