Make allometric exponents species-specific

[gustavdelius]

When MizerParams() calculates the size-dependent rates, it makes allometric assumptions for many rates. For example the metabolic loss scales as size to the power p, maximum intake rate scales as size to the power n and search volume scales as size to the power q. Currently these parameters are specified as arguments to MizerParams() (and its relevant constituent functions, like setMetab(), setIntakeMax() and setSearchVolume()). Hence the same values are used for all species.

Given that there is some evidence for variation in the scaling exponents across species and that the scaling exponents have quite a large effect on the shape of the within-species size distribution, I propose the option to specify the values for the exponents n, p and q via columns in the species parameter data frame, which would allow different values for different species if desired. Of course the default would not change and still be the same value for all species.

[astaaudzi]

I always assumed that mizer already allows users to specify n, p and q. At least I have them set in my species_params file (and at least the values I use are not mizer defaults)

[Kenhasteandersen]

It was previously not possible on a per-species basis. Ken

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--------------------------------------------------------------------------------------------------------------- Ken H. Andersen, http://ken.haste.dk<http://ken.haste.dk/>, twitter: @69kno Professor in theoretical marine ecology, head of section, and deputy director of Centre for Ocean Life http://www.oceanlifecentre.dk<http://www.oceanlifecentre.dk/> New book: Fish Ecology, Evolution, and Exploitation - A New Theoretical Synthesis https://press.princeton.edu/titles/13516.html [cid:image001.jpg@01D09493.A377DFB0] On 18 Sep 2019, at 06.15, Asta Audzi <notifications@github.com<mailto:notifications@github.com>> wrote: I always assumed that mizer already allows users to specify n, p and q. At least I have them set in my species_params file (and at least the values I use are not mizer defaults) — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<#92?email_source=notifications&email_token=ADFHLANX2URNCN2XYUAED7DQKGTN7A5CNFSM4IWWIRRKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD66XR6Q#issuecomment-532510970>, or mute the thread<https://github.com/notifications/unsubscribe-auth/ADFHLAIW7MRI7Y5UBR22O3TQKGTN7ANCNFSM4IWWIRRA>.