[R-sig-eco] Question related to rgeos package

2013-07-23 Thread Dylann Kersusan
Dear all, I am currently working on GPS relocations and more specifically on the study of territoriality (lynx and wolverine). I'd like to use the function gBuffer from the rgeos package to apply a buffer area to a home-range. What I'd like to get is the exact number of points included in the

[R-sig-eco] Two-sided significant test for null models

2013-07-23 Thread Cayetano Gutiérrez Cánovas
Dear all, I'd like to test the two-side significance of an observed value being lower or higher in comparison to a null distribution, but I don't know how to build this in R code. Can anybody help me with some code or any R function? Let's say 'null.dist' the null distribution, 'obs' the

Re: [R-sig-eco] Two-sided significant test for null models

2013-07-23 Thread Bob O'Hara
On 07/23/2013 12:06 PM, Cayetano Gutiérrez Cánovas wrote: Dear all, I'd like to test the two-side significance of an observed value being lower or higher in comparison to a null distribution, but I don't know how to build this in R code. Can anybody help me with some code or any R function?

Re: [R-sig-eco] Two-sided significant test for null models

2013-07-23 Thread Cayetano Gutiérrez Cánovas
Thanks Bob / Dylan: Bob: I am concerned with the possibility of increase the risk of false positives because two tests are actually performing. What do you think of multiplying p-value by 2 (the number of tests) to control risk? set.seed(10) rnorm(999)-null.dist obs-2.5 alpha-0.05

Re: [R-sig-eco] Two-sided significant test for null models

2013-07-23 Thread Rob Robinson
also consider ?p.adjust cheers rob ** The new Bird Atlas is coming: http://www.bto.org/shop/bird-atlas *** Dr Rob Robinson, Principal Ecologist British Trust for Ornithology, The Nunnery, Thetford, Norfolk, IP24 2PU Ph: +44 (0)1842 750050 E: rob.robin...@bto.org Fx: +44 (0)1842

[R-sig-eco] Question related to rgeos package

2013-07-23 Thread Weber, Marc
Once you create your buffer using gBuffer, you can run gIntersects using your GPS relocations and the buffer, i.e: within - gIntersects(GPS relocations, buffer) And then just do a table on the resulting matrix to see which are true, i.e.: table(within) This should give you exact number of

[R-sig-eco] create point grid within polygon

2013-07-23 Thread David García Callejas
Hi all, is it possible to create an object of class SpatialPoint/SpatialPointDataFrame, with a given resolution, constrained to a certain SpatialPolygon? In QGis, for example, I can create a rectangular layer of points and then clip it to the extent of a polygon. The ideal solution in R would be

[R-sig-eco] Heat Map for species - code from Numerical Ecology with R‏

2013-07-23 Thread Valerie Mucciarelli
Hello, I am relatively new to R and I am working through the code that is provided in the book Numerical Ecology with R:http://xa.yimg.com/kq/groups/19243105/1919134110/name/Numerical.pdf (pg 79)  and I have run across an error message that I can't seem to figure out.  I am using the vegan,

[R-sig-eco] R help

2013-07-23 Thread Amy Henry
Dear R experts, I fitted my spatial data to a glm.nb model. I decided to detect and correct for spatial autocorrelation using ME{spdep}. If the glm.nb model is not significant should I still check for spatial autocorrelation, i.e can removing spatial autocorrelation uncover significance? Also,

[R-sig-eco] How to combine multiple conditions to sum rows

2013-07-23 Thread MAUD BERLINCOURT
Dear R-list, I'm looking at association btw individuals. Below is an example of the dataset. id = individual i neighb1 = first individual associated with individual i neighb2 = second individual associated with individual i Etc nb_assoc = total number of association at time t date = date in