RE: [distance-sampling] Error Message
Stephen Buckland
Sarah, in line transect sampling, ‘effort’ is generally the line length (assuming each line is surveyed just once). You have given different line lengths for the same line. E.g. for line 1, you have given lengths of 0.88 and 1.49. Perhaps the distances have been read in as effort?
Steve Buckland
From: distance...@googlegroups.com [mailto:distance...@googlegroups.com]
On Behalf Of Sarah Moore Nicholson
Sent: 06 November 2015 19:03
To: distance-sampling
Subject: [distance-sampling] Error Message
> df_hr <- ds(data, truncation=10, key="hr", adjustment="cos")
Error in checkdata(data, region.table, sample.table, obs.table, formula) :
A sample has a non-unique "Effort", check data!
#here is an example of our data. As you can see the effort is non-unique for all samples. Samples are transects with each row #being an unique observation. Please Help!
> head(data)
Sample.Label Region.Label Area Effort distance
1 1 N 22655 2000 0.88
2 1 N 22655 2000 1.49
3 2 N 22655 2000 3.85
4 2 N 22655 2000 0.21
5 2 N 22655 2000 1.06
6 3 N 22655 2000 1.25
A sample has a non-unique "Effort", check data!
Thanks for your help...
Sarah
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Eric Rexstad
Sarah
We haven't seen all of your data, but my interpretation of the error message you received is that one of your transects has more than one lengths recorded for it. The records you show look fine, but I expect somewhere in your data there is a "Region.Label"
"Sample.Label" combination that has multiple efforts entered. Likely a simple data entry problem to resolve.
Sent: 07 November 2015 10:19
To: Sarah Moore Nicholson; distance-sampling
Subject: RE: [distance-sampling] Error Message
