|
19 | 19 | #' @keywords function prediction ypr
|
20 | 20 | #'
|
21 | 21 | #'
|
22 |
| -#' @details The Thompson and Bell model incorporates an iteration step simulating the |
23 |
| -#' stock by means |
24 |
| -#' of the \code{\link{stock_sim}} function. In case changes in gear |
25 |
| -#' characteristics - |
26 |
| -#' here measured in terms of Lc or tc, the length or age at first capture, |
27 |
| -#' respectively - |
28 |
| -#' should be explored, a list with selectivity information about the gear has |
29 |
| -#' to be provided and |
30 |
| -#' the prediction models make use of the selectivity \code{\link{select_ogive}} |
31 |
| -#' function. |
32 |
| -#' Sparre and Venema (1998) recommend to treat the last length class always as plus group. |
33 |
| -#' This model is very sensitive to zero observations in the ultimate length |
34 |
| -#' classes. If unrealistic results are returned, |
35 |
| -#' it is recommended to cut length classes with zero observations, group |
36 |
| -#' them in a plus group or to change the interval between |
37 |
| -#' length classes. |
38 |
| -#' Equations which are used in this function assume isometric growth, an |
39 |
| -#' assumption often not met. Further, the assumption that there is no relationship |
40 |
| -#' between the parental stock size and progeny |
41 |
| -#' over a wide range of fishing mortalities or exploitation values, |
42 |
| -#' respectively, is also said to be untrue. By default, the functions assume |
43 |
| -#' knife-edge recruitment and selection of gears (Sparre and Venema, 1998). |
44 |
| -#' |
45 |
| -#' |
46 |
| -#' @return A list with the input parameters and dependent on the model type following |
47 |
| -#' list objects: |
48 |
| -#' \itemize{ |
49 |
| -#' \item |
50 |
| -#' } |
| 22 | +#' @details The Thompson and Bell model incorporates an iteration step |
| 23 | +#' simulating the stock by means of the \code{\link{stock_sim}} function. In |
| 24 | +#' case changes in gear characteristics - here measured in terms of Lc or |
| 25 | +#' tc, the length or age at first capture, respectively - should be |
| 26 | +#' explored, a list with selectivity information about the gear has to be |
| 27 | +#' provided and the prediction models make use of the selectivity |
| 28 | +#' \code{\link{select_ogive}} function. Sparre and Venema (1998) recommend |
| 29 | +#' to treat the last length class always as plus group. This model is very |
| 30 | +#' sensitive to zero observations in the ultimate length classes. If |
| 31 | +#' unrealistic results are returned, it is recommended to cut length classes |
| 32 | +#' with zero observations, group them in a plus group or to change the |
| 33 | +#' interval between length classes. Equations which are used in this |
| 34 | +#' function assume isometric growth, an assumption often not met. Further, |
| 35 | +#' the assumption that there is no relationship between the parental stock |
| 36 | +#' size and progeny over a wide range of fishing mortalities or exploitation |
| 37 | +#' values, respectively, is also said to be untrue. By default, the |
| 38 | +#' functions assume knife-edge recruitment and selection of gears (Sparre |
| 39 | +#' and Venema, 1998). |
| 40 | +#' |
| 41 | +#' |
| 42 | +#' @return A list with the input parameters and dependent on the model type. |
51 | 43 | #'
|
52 | 44 | #'
|
53 | 45 | #' @references
|
@@ -217,5 +209,3 @@ ypr_sel <- function(param, FM_change, Lt, P){
|
217 | 209 |
|
218 | 210 | return(ret)
|
219 | 211 | }
|
220 |
| - |
221 |
| - |
0 commit comments