[R] Warning messages in Splancs package :: no non-missing arguments to min; returning Inf

[D]

Dear Barry,

I am new to R and I am sorry for the sens information. I am using R
2.8.1 for Windows.

Does the error come from the kernel2d function, or from the image function?
-- It comes from the kernel2d function.

Does it do that for any data points?
-- Not yet tried with other data, only two mentioned Shapefiles. They
are correctly structured.

Have you read the help for kernel2d? Have you tried the example in the
help(kernel2d) text?
-- I will look into it, thanks!

Have you ever had it work?
-- No, tries on two separate installations.

Thanks for the solution, I will test it right away.

Dejan

On Mon, Mar 30, 2009 at 09:43, Barry Rowlingson
<b.rowlingson at lancaster.ac.uk> wrote:
> On Mon, Mar 30, 2009 at 7:12 AM, D <eloquence2 at gmail.com> wrote:
>> Hi,
>>
>> I would need some help with the splans package in R.
>>
>> I am using a Shapefile (downloadable at)
>> http://rapidshare.com/files/215206891/Redlands_Crime.zip
>>
>> and the following execution code
>>
>>
>> setwd("C:\\Documents and
>> Settings\\Dejan\\Desktop\\GIS\\assignment6\\DataSet_Redlands_Crime\\Redlands_Crime")
>> library(foreign)
>> library(splancs)
>> auto_xy<-read.dbf("Auto_theft_98.dbf")
>> rob_xy<-read.dbf("Robbery_98.dbf")
>> auto.spp<-as.points(auto_xy$x/1000, auto_xy$y/1000)
>> rob.spp<-as.points(rob_xy$x/1000, rob_xy$y/1000)
>> image(kernel2d(auto.spp, bbox(auto.spp), h0=4, nx=100, ny=100),
>> col=terrain.colors(10))
>> pointmap(auto.spp, col="red", add=TRUE)
>>
>> I would need to analyze the relationship betweeb the two Shapefiles,
>> but I am receiving the following warning message and a blank output
>>
>>
>> Xrange is  1827.026 6796.202
>> Yrange is  1853.896 6832.343
>> Doing quartic kernel
>> Warning messages:
>> 1: In min(x) : no non-missing arguments to min; returning Inf
>> 2: In max(x) : no non-missing arguments to max; returning -Inf
>>
>>
>> Can someone help me with what am I doing wrong in the execution code?
>> I am getting a blank graph.
>
> Well, do some investigation. Does the error come from the kernel2d
> function, or from the image function? Does it do that for any data
> points? Have you read the help for kernel2d? Have you tried the
> example in the help(kernel2d) text? Have you ever had it work? What
> version of R are you using and so on. Please read the posting guide.
>
>  The manual for kernel2d says that the second argument has to be "A
> splancs polygon data set". But you've given it bbox(auto.spp). But
> bbox returns a matrix which is the wrong structure - the columns are
> min and max and the rows are X and Y. Plus it only has the corner
> points, not all four points of the box which splancs says it needs.
> There's also a clue in your output:
>
>  Xrange is  1827.026 6796.202
>  Yrange is  1853.896 6832.343
>
>  - but if you plot the points (which you should always do, to make
> sure you've read them in properly) you should see that the X range
> should be 6796 to 6832 and the Y range should be 1827 to 1853.
>
>  Solution: use the splancs bboxx() function that converts an sp-style
> bounding box to a splancs-style bounding box:
>
>  k = kernel2d(auto.spp, bboxx(bbox(auto.spp)), h0=4, nx=100, ny=100)
>  image(k)
>
>  Barry
>