From: Paul S. <pag...@ma...> - 2003-03-30 19:19:24
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Dan, I just tried this with a polygon and a line layer and it seemed to work fine (on a winXP machine). Any chance you can send me (or make available for download) your data and the steps you went through (or a saved classification file?). Also, was there any output in the command window that indicated an error? Cheers, Paul Dan Putler wrote: > Hi Paul, > > I've just had a chance to look at it. It is _very_ nicely done. It by > far and the way the best implementation of a classifier I've seen in any > of the open source GIS tools. However, the one thing that didn't work > is the map legend. When I pressed on the legend button I just got a > blank white window with a small block cursor outlined in black and > filled with white. I did the testing using Frank's 1.5.4 version on a > Windows ME machine. > > Dan > > Paul Spencer wrote: > >> Dan, I just checked Frank's 1.5.4 release and it is there. There is a >> 'classify raster' button on the toolbar (window with a C in it :)) >> that was not updated to reflect the fact that the classification >> screen can now handle vector data. This functionality hasn't been >> used much expect in my projects as far as I know so please give it a >> try and post feedback >> >> Cheers >> >> Paul >> >> Dan Putler wrote: >> >>> Hi Paul, >>> >>> This is great news. >>> >>> I have loaded up Frank's 1.5.4 version of OpenEV, in addition to the >>> 1.5.0 version available from the SourceForge site. Is this available >>> in 1.5.4, or do I need to build the latest from CVS to get at this? >>> >>> Dan >>> >>> Paul Spencer wrote: >>> >>>> Dan, >>>> >>>> this can be done in openev using the classification dialog. I >>>> recently (well, a few months ago) extended this to classify vector >>>> laters in addition to raster layers. >>>> >>>> Cheers, >>>> >>>> Paul >>>> >>>> Dan Putler wrote: >>>> >>>>> Hi, >>>>> >>>>> I was thinking about the ability to differentially shade polygons >>>>> in a layer based on a numeric (typically a float) field. The most >>>>> recent version of Thuban has this capability through what they call >>>>> a "classifier", as does GIS Toolkit and GeoTools using what they >>>>> call "shaders". The tools in Thuban and GIS Toolkit require a lot >>>>> of user intervention (the user has to categorize the data by hand), >>>>> while GeoTools (v1, but they are also likely to be in v2) provides >>>>> shaders that implement some basic categorization methods (pretty >>>>> much equal interval and equal frequency). On grasslist I've seen a >>>>> related discussion. The advise there was that with GRASS (at least >>>>> v5.0.x and below) you needed to translate a vector layer to a >>>>> raster layer, edit the raster layer, say several prayers, and then >>>>> you could get your map. My guess is that a similar process could >>>>> be followed in OpenEV, but boy it sounds really painful. It would >>>>> be much easier if these types of maps could be created directly >>>>> with a vector layer in OpenEV without the need to do the raster >>>>> conversion step. >>>>> >>>>> Hopefully this clarifies my earlier question. >>>>> >>>>> Dan >>>>> >>>>> Frank Warmerdam wrote: >>>>> >>>>>> Dan Putler wrote: >>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> My guess is that this question is likely to have been on this >>>>>>> list before, but I couldn't find it looking over the archives. >>>>>>> >>>>>>> My question is whether there are plans to include vector based >>>>>>> choropleth mapping capabilities in OpenEV in the future, or is >>>>>>> there already this capability and I'm just not clever enough to >>>>>>> find it? >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> Dan, >>>>>> >>>>>> There are no plans for chloropleth mapping that I am aware of. >>>>>> >>>>>> Do you mean deriving vector contour lines from a raster layer? >>>>>> Generating some sort of choropleth map from random point data? I >>>>>> am not >>>>>> that familiar with the technique, so perhaps you could elaborate. >>>>>> In part, I am wondering if it could be implemented fairly easily in >>>>>> Python using the existing rendering capabilities. >>>>>> >>>>>> Best regards, >>>>>> >>>>> >>>>> >>>> >>> >>> >> > > -- Paul Spencer Applications and Software Development DM Solutions Group Inc. http://www.dmsolutions.ca |