WR79 {FSA} | R Documentation |

## Ages and lengths for a hypothetical sample from Westerheim and Ricker (1979).

### Description

Ages and lengths for a hypothetical sample in Westerheim and Ricker (1979).

### Format

A data frame of 2369 observations on the following 3 variables:

- ID
Unique fish identifiers

- len
Length of an individual fish

- age
Age of an individual fish

### Details

Age-length data in 5-cm increments taken exactly from Table 2A of the source which was a sample from a hypothetical population in which year-class strength varied in the ratio 2:1 and the rate of increase in length decreased with age. Actual lengths in each 5-cm interval were simulated with a uniform distribution. The aged fish in this file were randomly selected and an assessed age was assigned according to the information in Table 2A.

### Topic(s)

### Source

Simulated from Table 2A in Westerheim, S.J. and W.E. Ricker. 1979. Bias in using age-length key to estimate age-frequency distributions. Journal of the Fisheries Research Board of Canada. 35:184-189.

### Examples

data(WR79)
str(WR79)
head(WR79)
## Extract the aged sample
WR79.aged <- subset(WR79,!is.na(age))
str(WR79.aged)
## Extract the length sample
WR79.length <- subset(WR79,is.na(age))
str(WR79.length)

[Package

*FSA* version 0.8.18

Index]