Latest Contributions by NeilAyres

‎03-25-2015

That's a lot of work if you have to do it on bigger or other datasets. It would be a better way forward to do some research on the origins of the data. And tell whoever captured the data not to just "rename" the datum.

‎03-25-2015

Thanks for posting. There are 3 tins here. Is there another set which is vertically above or below these ones? Don't forget that Extrude between can only extrude the portion where both top and bottom overlap.

‎03-25-2015

This sort of shift is caused by an incorrect datum (change in the underlying ellipsoidal model). I took your mainrivers shapefile, I see it is of the Mekong river in Cambodia. Yes, it's coordinate system is defined as UTM 47N and based on the WGS84 datum. However, if you assume that WGS84 is not the original datum for this data (depends on the source of these river polys, old carto sheets perhaps). I looked up at ASPRS Clifford Mugnier Grids & Datums page and also at EPSG.org. There are several suggestions as to the original classical datums used by the French authorities in colonial days. One of which is India1960. (Don't know why they would have used this). So, I copied the shapefile, gave it a new name, and then redefined the coord sys, changing the GCS to India 1960. So the blue is the original, the green te new one, and I have applied one of the available transforms between India1960 & WGS84. The base map in National Geographic (good enough in this case). You can see that the green one is much closer to the basemap image. The difference here between old and new is ~500m. The fit is not exact (I wouldn't expect it to be), because we do not know on which datum this data was originally based. The only thing we do know for sure is that it definitely wasn't WGS84.

‎03-24-2015

What do the 2 tins look like? I am trying to imagine how CreateTin makes a tin from only 4 points?

‎03-23-2015

Once you have the tins, use Surface Difference 3d http://resources.arcgis.com/en/help/main/10.2/index.html#//00q900000020000000 The output is a polygon feature with a class of -1 or 1 representing those areas of +ve or -ve difference and the volume therein.

‎03-23-2015

Regardless of how the graph is made, either manually or via a script, I think you still have to open the graph in ArcMap. View / Graph and then pick it. If you are creating the graph using arcpy / python, is this happening within an open ArcMap mxd?

‎03-12-2015

Xander, okay, I see what you are doing. And, yes, if I set the Data Type to Spatial Reference & use GetParameter There is no need to use arcpy.SpatialReference on the input variable, because it already is a SR object. Thanks, using v10.2.2

‎03-11-2015

In the image analysis window, what do those 2 extra variables do? Pixel Size power etc

‎03-11-2015

Having individual layers per polygon attribute as you note above is not really how the data should be organized. One layer with all the polygons which are identified by some sort of attribute is the way to go. Otherwise, editing edges between polygons / layers would be nightmare. As Dan says, simply select by attribute, then select by location.

‎03-11-2015

Dan, I know I can get a SR object from a describe of a feature. The point here is to set a SR from a script tool parameter. It seems the way to do it is as outlined in my first post. But I am very open to alternative suggestions. Perhaps someone from esri could advise how this is done, and put something in the help files to illustrate this.

‎03-11-2015

Did that, still doesn't work. If you look at your code above, you are printing the contents of the variable. Its still not an SR object.

‎03-10-2015

Xander, see this.. My code # test spatial reference import sys, os import arcpy SR = arcpy.SpatialReference(arcpy.GetParameter(0)) msg = "Coord sys is {}".format(SR.name) print msg arcpy.AddMessage(msg)

‎03-10-2015

A few thing here... When making geometries, supply the spatial reference : pg = arcpy.PointGeometry(p, sr) Your output shouldn't be a shapefile (*.shp) if its going into a gdb. You have to make your python code into a script tool. You use the GetParameterAsText(#) for each of your inputs. Then the script can be added to a toolbox as a script tool. Each input needs to have its properties set, so the tools knows what sort of input is expected (workspace, feature class etc) See here: http://resources.arcgis.com/en/help/main/10.2/index.html#//001500000006000000 http://resources.arcgis.com/en/help/main/10.2/index.html#//00150000000n000000

‎03-10-2015

Oh, and another thing... How do you get the advanced editor when starting a new thread so that you can do the code formatting correctly?

‎03-10-2015

I did try GetParameter, same result, it doesn't return a SR object, but a string! I looked and looked through the documentation and found no pointers how to do this. If the esri folk are listening, perhaps something should be in in the help files on how to do this. My solution works, but is there another way to do it?

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Date Last Visited	‎11-11-2020 02:23 AM

My Ideas

Latest Contributions by NeilAyres

Re: Layer does not match imagery by 400 meters..

Re: extrude between fail

Re: Layer does not match imagery by 400 meters..

Re: extrude between fail

Re: 3D surface volume

Re: Show a graph with python

Re: Getting a spatial reference from a script tool parameter

Re: Slope: Spatial Analyst vs Image Analysis

Re: Selecting items from one polygon within multi-polygon layer

Re: Getting a spatial reference from a script tool parameter

Re: Getting a spatial reference from a script tool parameter

Re: Getting a spatial reference from a script tool parameter

Re: Generate dynamic input with python script

Re: Getting a spatial reference from a script tool parameter

Re: Getting a spatial reference from a script tool parameter

Re: How to create contour lines/or raster from poi...

Re: Contour Lines Are Not Z-Enabled

Re: Finding maximum value between multiple rasters

Re: Converting DEM cell size from degrees to meter...

Re: Make Arcpy use Esri Feature Service

Coordinate Reference Systems