Error in ContourLines2SLDF(CLrp) : cL too short

On Mon, 27 Sep 2010, Maxime Pauwels wrote:

If you want to test the input, please find it here:

https://bigfile.univ-lille1.fr/get?k=sgVm6qmUdiCddAJlpzh

image(rangerp)
image(imgrp)

suggest that contour() will fail, as it does. Are you sure that the 
input data are correctly organised?

Roger

Maxime

Le 27/09/2010 13:34, Roger Bivand a ?crit :

On Mon, 27 Sep 2010, Maxime Pauwels wrote:

Hi list,

I have a message error using contourLines and ContourLines2SLDF
functions (maptools package).

rangerp<-read.table("NAhalleri.txt", header=T)
coordinates(rangerp)=~long+lat
gridded(rangerp)=TRUE
proj4string(rangerp)<-CRS("+proj=longlat")
imgrp<-as(rangerp,"SpatialGridDataFrame")
img1rp<-as.image.SpatialGridDataFrame(imgrp["V1"])
CLrp<-contourLines(img1rp, levels=0.0000878882)
CLSLrp<-ContourLines2SLDF(CLrp)
/Error in ContourLines2SLDF(CLrp) : cL too short/

Could anyone help understant what happens?

The levels= value is outside the range of values in img1rp:

library(maptools)
image(volcano)
summary(c(volcano))
CLrp <- contourLines(volcano, levels=70)
CLSLrp<-ContourLines2SLDF(CLrp)
# error
CLrp <- contourLines(volcano, levels=170)
CLSLrp<-ContourLines2SLDF(CLrp)
plot(CLSLrp, add=TRUE)
# OK

Hope this helps,

Roger

Can the input table be too long (3 columns, but almost 300 000 lines)?

Many thanks,

Maxime

Maxime Pauwels
Researcher ID: http://www.researcherid.com/rid/A-1745-2009

Laboratoire de G?n?tique et Evolution des Populations V?g?tales
FRE CNRS 3268
Universit? de Lille, USTL-Lille1
http://gepv.univ-lille1.fr
Tel : +33 3 20 33 62 38
Fax : +33 3 20 43 69 79

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