topic Re: Create polygon, clip features, export to dwg in Mapping Questions

Create polygon, clip features, export to dwg

AaronObermiller1 — Fri, 16 Oct 2015 14:59:56 GMT

Hello, the title says it all.
For the life of me, I can not figure out how to create a simple polygon that would allow me to clip shapefiles from within that polygon, then export to dwg. I'm fairly certain I have figured out how to complete the last part (geoprocessing -> clip; then ArcToolBox -> export to dwg), but I can not figure out the first part. Internet and forum searches have not been useful, I suspect I'm using the wrong terminology.

For an example of what I'm trying to do (and the sole reason I purchased the program yesterday):

Our county has 2ft contours in a shapefile. When I create a site sketch (in Autocad) I would like to import those contours into Autocad. So, in ArcMap, I find the piece of property and would like to select contours only within the approximate bounds of the property. The select feature grabs the full length of each contour. To reduce the file size, I would like to clip the contours only within the property boundary. This is where I'm stuck. It seems from my GIS classes 15 years ago, this was a fairly rudimentary function. Can someone please give me the baby steps?

This is, at this point and for the foreseeable future, the only function I will use ArcMap for. So while training is in the cards, it is time I cannot take away from work right now.

As a bonus question, though this is likely not the correct area, I have a fairly "high powered" computer Win 7x64, 6 core @ 3.8, 32 GB memory, FirePro W4100. ArcMap really bogs down when loading large data files, (the County contours @ 800MB). Like over 30 seconds to refresh the screen every time I zoom or pan too much. Is there any way to tell my computer to allow this program to command as much performance as it wants?

Re: Create polygon, clip features, export to dwg

IanMurray — Fri, 16 Oct 2015 15:14:10 GMT

If you have the parcels already in ArcGIS, select the parcel you need using the selection by location tool, or select by attribute. Once selected, go to that layer in the Table of Contents, right click>selection>create layer from selected feature. Then use that new layer is input for the clip.

If you need to create a new polygon for a custom area, open ArcCatalog, navigate to a folder where you want to create a new shapefile. Right click on the folder>New>Shapefile. Name it, change type to polygon, select spatial reference. You now have an empty polygon feature. Start an edit session(Customize>Toolbars>Edit, if you don't have it the editor toolbar up.), click the dropdown that say Editor>Start Editting Session>Select your new shapefile. Click on the Create Feature Icon, select your empty shapefile as template on the create features window. Create Polygons to you hearts content, save editting, then stop editting. Voila new polygon!

Alternatively if you have GE, much easier to make a new boundary there and convert from KML to Layer.

Re: Create polygon, clip features, export to dwg

RickeyFight — Fri, 16 Oct 2015 15:16:34 GMT

After you do the steps in Ian Post,

You need to clip the contours to the new polygon you just drew.

ArcGIS Help (10.2, 10.2.1, and 10.2.2)

Re: Create polygon, clip features, export to dwg

IanMurray — Fri, 16 Oct 2015 15:31:16 GMT

Also for better drawing performance, several good suggestions in this help.

ArcGIS Help 10.1

Also

arcgis desktop - How to improve rendering performance of very large shapefile? - Geographic Information Systems Stack Ex…

Re: Create polygon, clip features, export to dwg

DanPatterson_Retired — Fri, 16 Oct 2015 15:45:27 GMT

Are you trying to clip with a graphic shape? or a shape in an existing featureclass/shapefile?

check out this tool on Arcscripts Beta

http://www.arcgis.com/home/item.html?id=a9b032f739254ebeb6221c9294ebc886

I don't use graphics much so this may not be of any help if you are using that approach

Re: Create polygon, clip features, export to dwg

AaronObermiller1 — Fri, 16 Oct 2015 18:35:07 GMT

Excellent Mr. Murray, I very much appreciate the precise steps. Unfortunately the program would hang and crash after every major operation which wasted a lot of time, but when it was loaded back up, the steps had been completed and auto saved. I have successfully created, clipped and exported the data as I intended. Also, I did read through the performance suggestions, but the program settings are already set for hardware acceleration.

Re: Create polygon, clip features, export to dwg

AaronObermiller1 — Fri, 16 Oct 2015 18:51:52 GMT

Mr. Patterson, thank you for the link. That seems like it will perform well. I still need to figure out how to point to the target layer, but most of the plans I create involve rectangular parcels.