# tidy: Utilities to neaten permutation objects In permutations: The Symmetric Group: Permutations of a Finite Set

## Description

Various utilities to neaten word objects by removing fixed elements

## Usage

 ```1 2``` ```tidy(x) trim(x) ```

## Arguments

 `x` Object of class `word`, or in the case of `tidy()`, coerced to class `word`

## Details

Function `trim()` takes a `word` and, starting from the right, strips off columns corresponding to fixed elements until it finds a non-fixed element. This makes no sense for `cycle` objects; if `x` is of class `cycle`, an error is returned.

Function `tidy()` is more aggressive. This firstly removes all fixed elements, then renames the non-fixed ones to match the new column numbers. The map is an isomorphism (sic) with respect to composition.

## Value

Returns an object of class `word`

## Note

Results in empty (that is, zero-column) words if a vector of identity permutations is given

## Author(s)

Robin K. S. Hankin

`fixed`,`size`,`nicify_cyclist`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```tidy(as.cycle(5:3)+as.cycle(7:9)) as.cycle(tidy(c(as.cycle(1:2),as.cycle(6:7)))) nicify_cyclist(list(c(4,6), c(7), c(2,5,1), c(8,3))) data(megaminx) tidy(megaminx) # has 120 columns, not 129 stopifnot(all(unique(sort(unlist(as.cycle(tidy(megaminx)),recursive=TRUE)))==1:120)) jj <- megaminx*megaminx[1] stopifnot(identical(shape(jj),shape(tidy(jj)))) #tidy() does not change shape ```