[R] mat2listw function

Jim Lemon
Sat, 30 Nov 2013 09:43:23 -0000

On 11/30/2013 07:05 AM, Jacquelyn Pless wrote:
> Hi all,
>
> I am attempting to create a weights object and perform a Moran I test as
> well. I have a very large spatial weights matrix (roughly 22,000x22,000)
> that was created in Excel and read into R, and I'm now trying to
implement:
>
> library(spdep)
> SW=mat2listw(matrix)
>
> I am getting the following error:
> Error in if (any(x<0)) stop ("values in x cannot be
negative"): missing
> value where TRUE/FALSE needed.
>
> What's going wrong here? My current matrix is all 0's and 1's,
with no
> missing values and no negative elements. What am I missing?
>
> I'd appreciate any advice. Thanks in advance for your help!
>
Hi Jacquelyn,
The first thing I would do is enter:

sum(is.na(x))

and if anything other than zero is returned, you will know what's wrong.
Your dataset has been imported from Excel, and that application is
notorious for exporting things in the way it knows you want them to be. Not.

Jim