Description Usage Arguments Details Value References Examples

View source: R/gnomonic-main.R

Estimate natural mortality based on gnomonic interval approach.

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`nInterval` |
a numeric value that represents the number of gnomonic intervals. |

`eggDuration` |
a numeric value with the egg stage (first gnomonic interval) duration in days. |

`addInfo` |
a numeric vector with additional information related to the observed duration of the other gnomonic intervals different than the first interval (egg stage duration). Write |

`longevity` |
a numeric value indicating the lifespan of the species in days. |

`fecundity` |
a numeric value indicating the mean lifetime fecundity (MLF) as the number of eggs produced for a female. |

`a_init` |
a numeric value indicating the initial parameter related to the proportionality optimized by iterative solution via univariate (1-dim.) minimization. |

Estimate natural mortality (M) based on gnomonic interval approach.

The argument `nInterval`

is NULL by default. If you have -at least- one observed value for the duration of the other gnomonic intervals
you should provide this as a vector which length must be nInterval - 1, for example `addInfo = c(3, NA, NA, NA, NA, NA)`

) for a `nInterval = 7`

.

A list of class 'gnomos'.

`a`

the proportionality constant.

`G`

the constant proportion of the overall natural death rate.

`results`

a dataframe with the duration ("interval_duration_day") and natural mortality ("M_day" and "M_year") for each gnomonic interval.

Caddy JF (1996). Modelling natural mortality with age in short-lived invertebrate populations: definition of a strategy of gnomonic time division. Aquat Living Resour 9:197–207. doi: 10.1051/alr:1996023.

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#The values are based on Caddy (1996).
model <- gnomonic(nInterval = 7, eggDuration = 2, addInfo = NULL,
longevity = 365, fecundity = 200000, a_init = 2)
model
model$a
model$G
model$results
#Additional information for the duration of the second gnomonic intervals.
model <- gnomonic(nInterval = 7, eggDuration = 2, addInfo = c(3, NA, NA, NA, NA, NA),
longevity = 365, fecundity = 200000, a_init = 2)
model
model$a
model$G
model$results
``` |

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