Latest Contributions by DavidAskov1

Short(er) version of the question: I have a raster surface (decimal values) that I want to convert into 5 categories of polygons based on class breaks, and the output must be smooth and visually appealing. Using the "contour list" tool and line smoothing (PAEK method), I'm able to produce nice contour lines that are basically what I want, but I need polygons. Back in the raster world, using reclass (to convert to integer) and then "raster to polygon", I get a jumble of sliver polygons and ugly blocky edges. I could smooth these out, but it also doesn't create concentric rings in places where it increases sharply, so I get non-consecutive values adjacent to each other. The screenshot below shows what it looks like when I use raster to polygon without simplification, and the simplified version is an even worse mess. The nice contour lines are drawn over it. How can I get polygons that look like what I see with these contour lines?  Long(er) version of the question: My input is a raster surface (double), and I want to produce polygons as output for 5 classes based on thresholds. I have ArcGIS Desktop and access to all the extensions. Although I may be a data nerd who doesn't see any problem with blocky edges and sliver polygons, my marching orders were to produce nice, clean polygons that show the larger trends in the data and remove the micro-fluctuations in the data. In other words, it needs to be smooth and visually appealing, and I have creative license to get there. The raster is an air quality model, so it's not a conventional DEM terrain surface. There are massive fluctuations in the surface (Z) value in a very short distance, so contours will be very close to each other, but I do need them to be concentric, even if they are very narrow bands (like the contour lines above). I have already smoothed it and reduced the cell size to get this far. I suppose I could continue to smooth and resample until my raster data processing produces something similar to the contours. That said, I feel like I have what I want with the contours (visually), but I need polygons, not lines. I found an Esri help doc on converting contours to polygons saying to rasterize it and then run raster to polygon. This doesn't exactly fill me with confidence, since that is the process I'm fighting with already! Is there some contouring tool that will do what I have above, but with the lines filled in as polygons? ... View more

Hi all - I am trying to retrieve features from an ArcGIS Server 10.31 map service using the ArcGIS Python API and insert them into PostgreSQL/PostGIS. For the geometry, both use WKT, but they don't have the same format. Here is a snippet of what I run to get the data: import arcgis from arcgis.gis import GIS from arcgis.features import FeatureLayer from arcgis.geometry import Geometry perimetersLAYER = FeatureLayer('https://<URL>/arcgis/rest/services/<service>/MapServer/1') perimeters_feature_set = perimetersLAYER.query(where="objectid = 8605") for feature in perimeters_feature_set.features:     print('\n\n')     for field in feature.fields:         print(field + ': ' + str(feature.get_value(field)))         geom = Geometry(feature.geometry)     print('geom.WKT: ' + str(geom.WKT))     ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ The ArcGIS Python API Geometry response looks like this: MULTIPOLYGON (((-13645793.9305409509688616,  4645922.6947647286579013), (-13645734.9949775058776140,  4645907.8913778141140938), (-13645738.5948890540748835,  4645918.5636747097596526), (-13645706.8243041206151247,  4645943.8052548961713910), [SNIP] I'd like to pass this directly to a SQL insert with the PostGIS MULTIPOLYGON function, which looks like this: MULTIPOLYGON(((0 0 0,4 0 0,4 4 0,0 4 0,0 0 0),(1 1 0,2 1 0,2 2 0,1 2 0,1 1 0)),((-1 -1 0,-1 -2 0,-2 -2 0,-2 -1 0,-1 -1 0))) Note that the geometry formats are slightly different. In PostGIS, the x/y/z coords are space delimited and each vertex is comma delimited. The Esri geometry's x/y coords are comma delimited, and each vertex is wrapped in parentheses and also comma delimited. I can parse all the strings and munge the formats from one to another, but is there a way to automagically convert from one to another? It looks like Esri's WKT does not match the input PostGIS needs for its WKT functions. When I try the Geometry's WKB and JSON properties, it returns None, so I'm not sure where to go with that. Of course the geometry format is the minutia of my problem. The bigger picture issue is to find the shortest path from an ArcGIS Enterprise map service to PostGIS. If there's a better way, I'm all ears, though I'd like to keep it in python and run it on Linux. thanks! ... View more