[R-sig-Geo] Error in ContourLines2SLDF(CLrp) : cL too short

[Roger Bivand]

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 écrit :
>> 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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>>> regarder, ils s'habitueront.?
>>> Ren? Char
>>> 
>>> 
>>> [[alternative HTML version deleted]]
>>> 
>>> 
>> 
>
>
>

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no