# lagratio: Ratio of lagged observations. In FSA: Simple Fisheries Stock Assessment Methods

## Description

Computes the ratio of lagged observations in a vector.

## Usage

 ```1 2 3 4 5 6 7 8``` ```lagratio( x, lag = 1L, recursion = 1L, differences = recursion, direction = c("backward", "forward"), ... ) ```

## Arguments

 `x` A numeric vector or matrix. `lag` An integer representing the lag ‘distance’. `recursion` An integer that indicates the level of recursion for the calculations. A `1` will simply compute the ratios. A `2`, for example, will compute the ratios, save the result, and then compute the ratios of the results using the same `lag`. See examples. `differences` Same as `recursion`. Used for symmetry with `diff`. `direction` A string that indicates the direction of calculation. A `"backward"` indicates that ‘latter’ values are divided by ‘former’ values. A `"forward"` indicates that ‘former’ values are divided by ‘latter’ values. See examples. `...` Additional arguments to `diff()`.

## Details

This function behaves similarly to `diff()` except that it returns a vector or matrix of ratios rather than differences.

## Value

A vector or matrix of lagged ratios.

## Author(s)

Derek H. Ogle, derek@derekogle.com

`diff`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15``` ```## Backward lagged ratios # no recursion lagratio(1:10,1) lagratio(1:10,2) # with recursion lagratio(1:10,1,2) lagratio(1:10,2,2) ## Forward lagged ratios # no recursion lagratio(10:1,1,direction="forward") lagratio(10:1,2,direction="forward") # with recursion lagratio(10:1,1,2,direction="forward") lagratio(10:1,2,2,direction="forward") ```