Hi All,
Having corresponded offline with Ana, we've concluded the issues were
due to irregularities in the inputs (for example, a missing "size"
column in the data frame containing the observation distances). Anyway,
it's all resolved now. If anyone is experiencing similar issues, please
feel free to post to the list, or contact Eric or me directly.
Cheers, Len Thomas
> (<
Eric.R...@st-andrews.ac.uk <mailto:
Eric.R...@st-andrews.ac.uk>>)
> escribió:
>
> Only a guess Ana. I think the software identifies "k" by the number
> of unique values in the|Sample.Label| field. You mention
> |segments| in one of your comments, are your transects broken into
> segments? Are you treating segments as transects? Have you
> correctly assigned unique Sample.Labels to what you are treating as
> segments?
>
> ------------------------------------------------------------------------
> *From:*
distance...@googlegroups.com
> <mailto:
distance...@googlegroups.com>
> <
distance...@googlegroups.com
> <mailto:
distance...@googlegroups.com>> on behalf of Ana
> Cañadas <
anacan...@gmail.com <mailto:
anacan...@gmail.com>>
> *Sent:* 12 November 2021 21:16
> *To:* distance-sampling <
distance...@googlegroups.com
> <mailto:
distance...@googlegroups.com>>
> *Subject:* {Suspected Spam} [distance-sampling] problems with
> distance in R
> Hi,
> I am trying to run some detection functions in R and I am finding
> some troubles:
>
> 1- dht is not giving summary for clusters, only individuals. I don´t
> understand why (in my previous models I go both):
> image.png
>
> 2-For some reason it is not getting the right number of segments (k)
> and total effort (Effort), but much smaller, therefore creating a
> huge estimate. For more than I check, I can´t find why. Everything
> is in km:
> > region.table$Area
> [1] 129153
> > sum(sample.table$Effort) *km on effort
> [1] 18226.86
> > nrow(sample.table) *number of segments
> [1] 3717
> > nrow(obs.table)
> [1] 165
> > range(obs.table$distance)
> [1] 0.000000 2.178789
> > trunc *right truncation
> [1] 0.734
> > nrow(obs.table[obs.table$distance<=trunc,]) *number of
> observations after truncation
> [1] 157
>
> Compare this with the summary in dht:
> image.png
>
>
> Here n is correct (157) and so is Area (129153), but k is 135 when
> it should be 3717, and Effort is 677 when it should be 18227. There
> is no stratification in the study area or anything that could lead
> to confusion.
>
> I´ve been investigating this for hours without reaching any
> conclusion or advancing at all. So at this stage, any help would be
> very welcome. Hopefully it is just something stupid I am doing and
> which I cannot see now...and that some extra eyes may find!
>
> Many thanks in advance
> Ana
>
> --
> You received this message because you are subscribed to the Google
> Groups "distance-sampling" group.
> To unsubscribe from this group and stop receiving emails from it,
> send an email to
distance-sampl...@googlegroups.com
> <mailto:
distance-sampl...@googlegroups.com>.
> <
https://groups.google.com/d/msgid/distance-sampling/CAKfiqX1%3Dxaj-8c7-d1Xr%2BaiVE6ELDKqeQSrnHtV3kakA9P1kYA%40mail.gmail.com?utm_medium=email&utm_source=footer>.
>
> --
> You received this message because you are subscribed to the Google
> Groups "distance-sampling" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to
distance-sampl...@googlegroups.com
> <mailto:
distance-sampl...@googlegroups.com>.
> To view this discussion on the web visit
>
https://groups.google.com/d/msgid/distance-sampling/CAKfiqX0w_6HaGK0h1V-f-%2BVXpLVJ2-R8K0CrMZZtiKeF9yaLBg%40mail.gmail.com
> <
https://groups.google.com/d/msgid/distance-sampling/CAKfiqX0w_6HaGK0h1V-f-%2BVXpLVJ2-R8K0CrMZZtiKeF9yaLBg%40mail.gmail.com?utm_medium=email&utm_source=footer>.
--
Len Thomas (he/him)
len.t...@st-andrews.ac.uk lenthomas.org @len_thom
Centre for Research into Ecological and Environmental Modelling
and School of Mathematics and Statistics
The Observatory, University of St Andrews, Scotland KY16 9LZ
Office: UK+1334-461801 Admin: UK+1334-461842
While I may be sending this email outside of my normal office hours,
I have no expectation to receive a reply outside of yours.
The University of St Andrews is a charity
registered in Scotland, No SC013532.