spsample bug?

On 11/05/16 14:51, Juta Kawalerowicz wrote:

Hi I encountred a problme when running a loop to generate randomly
distributed points within a polygon. The error I get is:

Error in .local(x, n, type, ...) :
iteration did not converge; try enlarging argument iter

did you try enlarging argument iter? For me this worked:

  ...
  points <- spsample(dry.grid.u, n = n, type = "random", iter = 6)

Here is the code which allows to get this error (although you will get it
for different i). Any ideas would be much appreciated.

Juta

###import polygon shapefile from Dropbox
con <- url("

https://www.dropbox.com/s/b6v2e14dr6rn3zw/spsample.RData?raw=1")

load(con)

#see what's inside
plot(dry.grid.u, col="red", axes=TRUE)
class(dry.grid.u)

#let's say we want 11 points generated
n<-11
#works fine for doing it just once
points<-spsample(dry.grid.u,n=n,type="random")
plot(points, add=TRUE)

#but when looped over many times there is a problem

  for (i in 1:5000){
    print(i)
    points<-spsample(dry.grid.u,n=n,type="random")
  }

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--
Edzer Pebesma
Institute for Geoinformatics  (ifgi),  University of M?nster
Heisenbergstra?e 2, 48149 M?nster, Germany; +49 251 83 33081
Journal of Statistical Software:   http://www.jstatsoft.org/
Computers & Geosciences:   http://elsevier.com/locate/cageo/
Spatial Statistics Society http://www.spatialstatistics.info