Timeline for Calculating viewing angle (2D) between polygons and points [closed]
Current License: CC BY-SA 4.0
21 events
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| May 16, 2019 at 22:23 | history | edited | PolyGeo♦ | CC BY-SA 4.0 |
added 76 characters in body; edited title
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| May 2, 2019 at 13:21 | comment | added | GIS_City | Thank you for all your answers. I guess they showed me that my question was much to general. Therefore i think i will ask a new question in a new post that is more concrete. | |
| Apr 30, 2019 at 21:14 | history | closed |
Vince Fran Raga whyzar PolyGeo♦ |
Needs details or clarity | |
| Apr 30, 2019 at 21:14 | comment | added | PolyGeo♦ |
If you decide to ask about code to do this we ask that you show us where you are stuck with your own code by including a code snippet in your question. There is an edit button beneath your question which will enable you to do that and a {} button that enables you to format any highlighted code nicely.
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| Apr 30, 2019 at 21:14 | comment | added | PolyGeo♦ | Welcome to GIS SE! We're a little different from other sites; this isn't a discussion forum but a Q&A site. Please check out our short tour to learn about our focussed Q&A format. If your "real question is, how do I get the coordinates of the vertices" then I think that you should use the edit button beneath your question to revise it to make that the single question that you wish to ask. | |
| Apr 30, 2019 at 20:43 | history | edited | csk |
edited tags
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| Apr 30, 2019 at 20:30 | comment | added | csk | @vince I think your second comment provided enough insight to post as an answer. It provides a conceptual approach, while leaving the coding up to the OP. | |
| Apr 30, 2019 at 12:19 | comment | added | Vince | You don't need three points, just two. Compute bearing from first point to first vertex, and then compute min/max of vertices from there on (wrapping by twoPi as necessary). Coding questions here are expected to contain code, so you need to set up the nested poly by point query loop at a minimum. | |
| Apr 30, 2019 at 12:12 | comment | added | Vince |
arcpy.da.SearchCursor documentation shows how to iterate shapefile rows, and using SHAPE@XY field token will give you a list of coords to walk.
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| Apr 30, 2019 at 12:10 | comment | added | GIS_City | My idea was to calculate the angle. For that I need the length of the three sides of the triangle. in order to calculate these I need the coordinates of the polygon vertices. The real question is, how do I get the coordinates of the vertices. Sorry for the misunderstanding | |
| Apr 30, 2019 at 11:55 | comment | added | GIS_City | I guess my description was a misunderstanding. I know how to calculate trigonometry.What I don't know is how I can coordinate the polygon vertex. Therefore I do need help. | |
| Apr 30, 2019 at 10:45 | review | Close votes | |||
| Apr 30, 2019 at 21:15 | |||||
| Apr 30, 2019 at 10:25 | comment | added | Vince | No, you can't use Excel for this, since it cannot access the geometry. If trig isn't a problem, I suggest you just get started, computing the angle from each observation point to every polygon vertex, identifying the gap which exceeds 180°, capturing the minimum and maximum from that gap, and the center from the minimum and maximum. You've framed the problem, so now it's time to code. If you run into a problem update the question with details. | |
| Apr 30, 2019 at 6:53 | comment | added | GIS_City | I use ArcGIS with a standard license without any extensions. But I could also switch to qgis if there are the necessary functions. Dealing with trigonometry is not a problem, it does not have to be done in GIS. I can also use excel for that. | |
| Apr 29, 2019 at 15:01 | history | tweeted | twitter.com/StackGIS/status/1122878460823781376 | ||
| Apr 29, 2019 at 14:02 | history | edited | Vince | CC BY-SA 4.0 |
title case
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| Apr 29, 2019 at 14:02 | comment | added | Vince | What software are you using? What extensions or plugins do you have available? Calculating visibility is simple enough with the right tools, at which point computing the furthest angles is also easy. Without those tools, it's still fairly simple, but you need to be prepared to do a great deal of trigonometry. | |
| Apr 29, 2019 at 13:56 | history | edited | Vince | CC BY-SA 4.0 |
removed welcomeness
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| Apr 29, 2019 at 13:43 | history | edited | GIS_City | CC BY-SA 4.0 |
edited title
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| Apr 29, 2019 at 13:30 | review | First posts | |||
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| Apr 29, 2019 at 13:29 | history | asked | GIS_City | CC BY-SA 4.0 |