alba {TropFishR}

Length-frequency data of the clam Abra alba

Description

Length-frequency data of the clam Abra alba as presented by Brey et al. (1988). Includes 7 approximately bi-monthly samplings of A. alba binned into 14 length classes. The data is of class "lfq", which can be used used e.g. in functions estimating growth parameters: ELEFAN, ELEFAN_SA or ELEFAN_GA.

Usage

data(alba)

Format

A list of class lfq consisting of:

• dates dates of sampling times (class Date),

• midLengths midpoints of the length classes,

• catch matrix with catches/counts per length class (row) and sampling date (column).

Source

Brey, T., Soriano, M., and Pauly, D. 1988. Electronic length frequency analysis: a revised and expanded user's guide to ELEFAN 0, 1 and 2. ICLARM Contrib. 261.

Examples

data(alba)

# plot raw catch frequencies
plot(alba, Fname = "catch")

# plot restructured frequencies
alba <- lfqRestructure(alba, MA=5)
plot(alba, Fname = "rcounts")


# ELEFAN_SA fitting
set.seed(1)
fitSA <- ELEFAN_SA(
  alba, seasonalised = TRUE,
  init_par = list(Linf=14.5, K=1.1, t_anchor=0.4, ts=0, C=0.2),
  low_par = list(Linf=13, K=0.7, t_anchor=0, ts=0, C=0),
  up_par = list(Linf=15.5, K=1.5, t_anchor=1, ts=1, C=1),
  SA_time = 60
)
unlist(fitSA$par)
fitSA$Rn_max

# plot ELEFAN_SA results
plot(alba, Fname = "catch", draw = FALSE)
lfqFitCurves(fitSA, col=2, par=fitSA$par, draw=TRUE)$Rn_max