[Qgis-developer] SDA4PP Kernel density troubleshooting

[Giovanni Manghi]

Hi,

> So there's a first question: can I use the plugin not only with 1.4.0 qgis,
> but also in 1.6.0 (my current one) or even in 1.7.0?

yes you can,
the installation of the dependencies for the plugins that rely on R is
tricky under Windows especially, Under Vista/Seven.

You need to use an "old" version of R (2.11, as rpy2 was not yet updated
to cope with the changes in R >= 2.12), add the path to the R binaries
in the Windows "path" environment variable, install the necessary
libraries (see the plugin documentation) and, under Vista/Seven, copy
the folder with the R libraries in another location.

See this wiki page related to another plugin (based on R) that can help
you understand the issues

http://www.qgis.org/wiki/HomeRange_plugin

I also noticed that many times under Windows, when installing R packages
from the R console, it "fail" to install the requested package (but
install its dependencies), so it is needed to re-issue the command.

See here to understand better what I'm saying

http://ubuntuone.com/p/zon/


> I have point data in form of .gpx file (points with coords). When I open it
> as a vector layer in qgis (waypoints) and try to run "Kernel density" (part
> of plugin) or any other like "Uniform density", "Adaptive density" which I
> have no idea whate they do, I get the same result. *The error message:*
> 
> An error occured:
> Error in ogrInfo(dsn = dsn, layer = layer, input_field_name_encoding =
> input_field_name_encoding) : 
>   Cannot open layer
> 
> Though now when I'm trying to solve the problem I'm not getting the same
> errors as yesterday (some coding related stuff), still it's not working.
> Yesterday there where also some ANSI problem. So I tried to change it
> (Mapsource I use to manage .gpx files doesnt have an option to choose coding
> of a text in it (ANSI, Unicode,...), notepad has (but opens .csv not .gpx).
> But after opening the same stuff, only .csv in notepad I found it's coded in
> ANSI. And qgis doesnt open .csv files.
> So although I have no experience in using that plugin (and honestly not much
> in any way), I cannot even run the plugin properly.
> 
> SDA4PP version 0.196
> 
> If anyone has an idea to solve this problem and help me out, I would
> appreciate it.

after adding your gpx to QGIS save it as a shapefile. Then check if you
have fields (column names) with non ascii letters, if I remember
correctly the plugin do not handle correctly such letters.


cheers

-- Giovanni --