Creates a function for a specific model based on definitions in Vigliola and Meekan (2009).
bcFuns(BCM)A single numeric between 1 and 22 or a string that indicates which model to use (based on numbers and names in Vigliola and Meekan (2009)).
A function that can be used to predict length at previous age (Li) given length-at-capture (Lcap), hard-part radius-at-age i (Ri), and hard-part radius-at-capture (Rcap). In addition, some functions/models may require the previous age (agei) and the age-at-capture (agec), certain parameters related to the biological intercept (R0p & L0p), or certain parameters estimated from various regression models (a,b,c,A,B,C). See source for more information.
The following models, based on definitions with abbreviations and model numbers from Vigliola and Meekan (2009), are supported.
| Abbreviation | Number | Model |
| DALE | 1 | Dahl-Lea |
| FRALE | 2 | Fraser-Lee |
| BI, LBI | 3 | (Linear) Biological Intercept |
| BPH, LBPH | 4 | (Linear) Body Proportional Hypothesis |
| TVG | 5 | Time-Varying Growth |
| SPH, LSPH | 6 | (Linear) Scale Proportional Hypothesis |
| AE, AESPH | 7 | (Age Effect) Scale Proportional Hypothesis |
| AEBPH | 8 | (Age Effect) Body Proportional Hypothesis |
| MONA | 9 | Monastyrsky |
| MONA-BPH | 10 | Monastyrsky Body Proportional Hypothesis |
| MONA-SPH | 11 | Monastyrsky Scale Proportional Hypothesis |
| WAKU | 12 | Watanabe and Kuroki |
| FRY | 13 | Fry |
| MF, ABI | 14 | Modified Fry, Allometric Biological Intercept |
| FRY-BPH, ABPH | 15 | Fry, Allometric Body Proportional Hypothesis |
| FRY-SPH, ASPH | 16 | Fry, Allometric Scale Proportional Hypothesis |
| QBPH | 17 | Quadratic Body Proportional Hypothesis |
| QSPH | 18 | Quadratic Scale Proportional Hypothesis |
| PBPH | 19 | Polynomial Body Proportional Hypothesis |
| PSPH | 20 | Polynomial Scale Proportional Hypothesis |
| EBPH | 21 | Exponential Body Proportional Hypothesis |
| ESPH | 22 | Exponential Scale Proportional Hypothesis |
Vigliola, L. and M.G. Meekan. 2009. The back-calculation of fish growth from otoliths. pp. 174-211. in B.S. Green et al. (editors). Tropical Fish Otoliths: Information for Assessment, Management and Ecology. Review: Methods and Technologies in Fish Biology and Fisheries 11. Springer. [Was (is?) available from https://www.researchgate.net/publication/226394736_The_Back-Calculation_of_Fish_Growth_From_Otoliths.]
## Simple Examples
( bcm1 <- bcFuns(1) )
#> function (Lcap, Ri, Rcap, ..., verbose = TRUE)
#> {
#> if (verbose)
#> DONE("Using the Dahl-Lea model.")
#> (Ri/Rcap) * Lcap
#> }
#> <bytecode: 0x000001b3c7d034f8>
#> <environment: 0x000001b3c469d568>
bcm1(20,10,40)
#> ✔ Using the Dahl-Lea model.
#> [1] 5
## Example with dummy length-at-cap, radii-at-cap, and radii-at-age
lencap <- c(100,100,100,150,150)
radcap <- c(20,20,20,30,30)
rad <- c( 5,10,15,15,25)
bcm1(lencap,rad,radcap)
#> ✔ Using the Dahl-Lea model.
#> [1] 25 50 75 75 125
( bcm2 <- bcFuns("FRALE") )
#> function (Lcap, Ri, Rcap, a, ..., verbose = TRUE)
#> {
#> if (verbose)
#> DONE("Using the Fraser-Lee model with a=", a, ".")
#> a + (Lcap - a) * (Ri/Rcap)
#> }
#> <bytecode: 0x000001b3c7d02fb8>
#> <environment: 0x000001b3c220ea40>
bcm2(lencap,rad,radcap,2) # demonstrated with a=2
#> ✔ Using the Fraser-Lee model with a=2.
#> [1] 26.5000 51.0000 75.5000 76.0000 125.3333