As many as 10 fish per 1-inch total length intervals from the StripedBass2 data frame were obtained for age assignment. The remaining fish in the file were only measured for length (i.e., the ages were deleted). This data file can be used to demonstrate the use of age-length keys.
Format
A data frame of 1201 observations on the following 2 variables:
- tl
Measured total lengths (in inches).
- age
Ages assigned from examination of otoliths.
Examples
data(StripedBass3)
str(StripedBass3)
#> 'data.frame': 1201 obs. of 2 variables:
#> $ tl : int 18 18 18 18 18 18 18 18 18 18 ...
#> $ age: int 2 2 2 2 3 3 4 4 5 7 ...
head(StripedBass3)
#> tl age
#> 1 18 2
#> 2 18 2
#> 3 18 2
#> 4 18 2
#> 5 18 3
#> 6 18 3
## Extract the aged sample
sb.aged <- subset(StripedBass3,!is.na(age))
str(sb.aged)
#> 'data.frame': 256 obs. of 2 variables:
#> $ tl : int 18 18 18 18 18 18 18 18 18 18 ...
#> $ age: int 2 2 2 2 3 3 4 4 5 7 ...
## Extract the length sample
sb.length <- subset(StripedBass3,is.na(age))
str(sb.length)
#> 'data.frame': 945 obs. of 2 variables:
#> $ tl : int 18 18 18 18 18 18 18 18 18 18 ...
#> $ age: int NA NA NA NA NA NA NA NA NA NA ...