bcFuns {FSA}R Documentation

Creates a function for a specific back-calculation model.


Creates a function for a specific back-calculation model based on definitions in Vigliola and Meekan (2009).


bcFuns(BCM, verbose = FALSE)



A single numeric between 1 and 22 or a string that indicates which back-calculation model to use (based on numbers and names in Vigliola and Meekan (2009)).


A logical that indicates whether a message about the model and parameter definitions should be output.


The following back-calculation 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


A function that can be used to predict length at previous age (Li) given length-at-capture (Lc), hard-part radius-at-age i (Ri), and hard-part radius-at-capture (Rc). 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.

IFAR Supplement



Derek H. Ogle, derek@derekogle.com


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) )

## 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)

( bcm2 <- bcFuns("FRALE") )
bcm2(lencap,rad,radcap,2)  # demonstrated with a=2

[Package FSA version 0.8.18 Index]