Dear list,
After reading different mails, blogs, and tried a few different codes without
any success, I am asking your help!
I have the following data frame where each row represent a survey unit with the
following variables:
> names(RV09)
[1] "record.t" "trip" "set" "month" "stratum" "NAFO"
[7] "unit.area" "time" "dur.set" "distance" "operation" "mean.d"
[13] "min.d" "max.d" "temp.d" "slat" "slong" "spp"
[19] "number" "weight" "elat" "elong"
Each survey unit generates one set record, denoted by a 5 in column "record.t".
Each species identified in this particular survey unit generates an additional
set record, denoted by a 6.
> unique(RV09$record.t)
[1] 5 6
Each survey unit are identified by a specific "trip" and "set" number, so if
there is a 5 record type with no associated 6 records, it means that no species
were observed in that survey unit. I would like to be able to select all and
only these survey units, which represent my zeros.
So as an exemple, in this trip number 913, set 1, 3, and 4 would be part of my
"zeros" data.frame as they appear with no record.t 6, such that no species were
observed in this survey unit.
> head(RV09)
record.t trip set month stratum NAFO unit.area time dur.set distance
585 5 913 1 10 351 3O R31 1044 17 9
586 5 913 2 10 351 3O R31 1440 17 9
587 6 913 2 10 351 3O R31 1440 17 9
588 5 913 3 10 340 3O Q31 1800 18 9
589 5 913 4 10 340 3O Q32 2142 17 9
Any tips on how extract this "zero" data.frame in R?
Thank you very much in advance!
Best,
~Aurelie
Aurelie Cosandey-Godin
Ph.D. student, Department of Biology
Industrial Graduate Fellow, WWF-Canada
Dalhousie University | Email: god...@dal.ca
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
