topic Re: Delete point features in point layer in Geoprocessing Questions

Delete point features in point layer

manuelrainer — Thu, 21 Apr 2011 03:18:32 GMT

Hi,

I have to do a point deletion in a point layer. It's a layer with regular spreaded points containing current values. So, if there is no water there are no points, of course. I cannot select features by attribute (e.g. mod("fid",20) = 0 for each 20th point) because then i get an irregular point selection. If I try do create a buffer around each point, ArcGIS hangs because I have more than 1million points in the layer. I thought I could do it in the way I create a grid with a certain cell size and for all points which are within a cell I intersect the point which overlaps with the calculated centroid... Is that possible without complex scripting and does anyone have better and easier solutions??

Thanks for help

Re: Delete point features in point layer

DarrenWiens2 — Thu, 21 Apr 2011 14:11:00 GMT

Can you describe what you're trying to do a little more clearly? Are you trying to resample your grid to a coarser scale?

Re: Delete point features in point layer

manuelrainer — Fri, 22 Apr 2011 13:29:58 GMT

You are right. I want to resample the grid to a coarser scale, but without interpolation. Just want to have the same grid with less regular spread points.

Re: Delete point features in point layer

DarrenWiens2 — Tue, 26 Apr 2011 15:54:24 GMT

Is it OK to have the coarse grid offset from your original grid? If so, here's my suggestion:

1.) You've got your original grid (here 100m x 100m).
2.) Make a new empty raster of your area of interest (Create Constant Raster tool) with coarse cell size (here, 1000m x 1000m). Use Raster to Point tool to create a point grid.
3.) Use Spatial Join tool to give coarse grid points the attribute of the nearest point in the original grid (for whatever reason, using the Join from the feature layer right-click menu didn't work).

Re: Delete point features in point layer

manuelrainer — Wed, 27 Apr 2011 06:47:13 GMT

Since I believe that it's the easier way to have an offset, yeah your suggestion helped me a lot. I am also trying to use some Spatial Analyst tools together with an analysis mask. Thank you!

Re: Delete point features in point layer

DarrenWiens2 — Wed, 27 Apr 2011 14:10:11 GMT

Actually, if you want to have the coarse grid overlay your original grid, you could add the coordinates to the original table (Add XY Coordinates tool), join the nearest points to the coarse grid, export the resulting table, then use "Display XY Data..." on that table.

Re: Delete point features in point layer

manuelrainer — Thu, 28 Apr 2011 01:23:33 GMT

GREAT!!!!! That is absolutely what I wanted to have 😄
Thank you so much for your support. I really really appreciate that!