multipliers by strata

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Jun 10, 2021, 1:16:43 PMJun 10
to distance-sampling
Hi folks,

I'm analysing and stratified distance survey, and I'm interested in including a strata-specific multiplier. However, I don't know how to handle 'dht2' function for that. Concretely, I'm considering 4 different stratas. 

If I run this, I'm considering a global multiplier for all the strata:
mult <- list(decay = data.frame(rate=c(0.41), SE=c(0.07)))
res_dens <- dht2(model_select, flatfile=dat, strat_formula = ~Region.Label, 
                 er_est = "P2", convert_units = conversion, stratification="geographical",
                 multipliers = mult)

I've tried with this:
mult <- list(decay = data.frame(rate=c(0.41, 0.47, 0.47, 0.36), SE=c(0.07, 0.06, 0.07, 0.08)))
and also by creating 4 different 'mult' objects, and later: multipliers =c(mult1, mult2, mult3, mult4)

but nothing works... 
It is possible to define a specific multiplier to each strata on 'dht2' function? Or I should include that on the 'Effort' column of my data frame?

Thank you very much for your help :)

Eric Rexstad

Jun 11, 2021, 3:28:34 AMJun 11
to PABLO PALENCIA MAYORDOMO, distance-sampling


Unfortunately, the ability to specify stratum-specific multipliers is not yet implemented in `dht2`.  If you are using multipliers to compensate for viewable area as you discussed in your earlier question, then you could incorporate that compensation into your Effort measures.

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Eric Rexstad
Centre for Ecological and Environmental Modelling
University of St Andrews
St Andrews is a charity registered in Scotland SC013532


Jun 11, 2021, 3:31:54 AMJun 11
to distance-sampling
Yes, that is. Thank you very much for your response!
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