[R-sig-Geo] RPyGeo Query -- probably easy

[Alexander Brenning]

Hi Zev,

the problems are definitely your quotes. First, they are syntactically 
incorrect - I count seven double quotes (I recommend using some editor 
with syntax highlighting, like Tinn-R or R-WinEdt, this helps discover 
mismatches). Second, escaping them (\") should allow you to put double 
quotes inside a double-quoted character string.

This might be closer to what you want to do (but I haven't tried to run 
it - sorry, busy end of term...):

rpygeo.geoprocessor("makefeaturelayer('X:\\abc.shp','walk')",
     "SelectLayerByAttribute('walk','NEW_SELECTION','\"hrwk05\"<>0')",
     env=myenv)

Note that an additional argument clean.up=FALSE to the 
rpygeo.geoprocessor allows you to inspect the Python file to check 
whether the quotes are syntactically correct in Python.

I hope this helps
  Alex



Zev Ross wrote:
> Hi All,
> 
> I'm wondering if anybody could give me a little guidance on formatting a 
> query using RPyGeo. I'm excited to be able to run Python geoprocessing 
> functions straight from R but am having trouble with the quote, double 
> quote kinds of issues.
> 
> Here's an example of what I'd like to run
> 
> rpygeo.geoprocessor("makefeaturelayer('X:\\abc.shp',
> 'walk')", "SelectLayerByAttribute('walk','NEW_SELECTION', ' "hrwk05" 
> '<>0")",env=myenv)
> 
> Where the sticking point is hrwk05 <> 0. In Python my query would be 
> double quote, field name, close double quote, comparison, number e.g, 
> "hrwk05" <> 0 but I'm not sure how to put this into RPyGeo
> 
> If I run like so:
> 
> rpygeo.geoprocessor("makefeaturelayer('X:\\abc.shp',
> 'walk')", "SelectLayerByAttribute('walk','NEW_SELECTION', '')",env=myenv)
> 
> it runs.
> 
> Thank you in advance for assistance.
> 
> Zev
> 

-- 
Alexander Brenning
brenning at uwaterloo.ca - T +1-519-888-4567 ext 35783
Department of Geography and Environmental Management
University of Waterloo
200 University Ave. W - Waterloo, ON - Canada N2L 3G1
http://www.fes.uwaterloo.ca/geography/faculty/brenning/