I'm using Arcmap 10, I need to create a raster from contour lines. These contour lines were clipped out with a certain shape with the purpose to modify them only within that shape and then create the raster from these modified contour lines. The problem is that when I come to the TopoToRaster step, the resulting raster is rectangular, while I'd need it with the shape I used for the clipping. How can I do this? Should I change some options in the Spatial Analyst? How?
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2Is there any problem with just clipping the resulting raster to the same shape used to clip the contour lines? – whuber Jun 18 '13 at 14:38
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I'm not sure about this and it's not easy to me to understand by just observing the results, but I would say that computing a raster (with topo to raster) starting from the same contours, first in a rectangular shape, than in a different shape produces different rasters also for what concerns the common area. I hope I made myself clear (English is not my language). Please let me know your opinion about this. Thank you! – Michele Cordini Jun 18 '13 at 16:50
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You might be right--I haven't tested this--but if that is the case, you ought to view the result with the non-rectangular shape as being influenced by an artificial, irrelevant piece of information (the clipping shape). I would therefore be inclined to use the rectangular grid and fair it back into the original grid, as you asked at gis.stackexchange.com/questions/63531/raster-smoothing. – whuber Jun 18 '13 at 16:53
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Excuse me, I did'n really get what you mean. In particulat what you mean with "fair it back". I saw that the best solution was to use the "smooth line" tool to work on the contours (of a clipped area), since for my previous question no final solution was proposed (if I well understood), right? thank you again for your tenacity! – Michele Cordini Jun 18 '13 at 17:38
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I'm sorry, the answer offered there is not a "best solution": it's not even a solution at all. That question still needs an adequate answer. – whuber Jun 18 '13 at 17:42
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Before performing topo to raster, you need to add a single polygon (input) which will be your desired boundary and change type to boundary (yes there is a dropdown key there).
The Clip_management Tool will clip a Raster to a real geometry outline. It is located in the Data Management\Raster Toolset. The 6th parameter is where you define "clipping_Geometry" (polygon perimeter). The default is to clip to an extent. Perhaps you can run Clip_management after TopoToRaster.
