topic Re: Calculator of polygon directions in Data Management Questions

Calculator of polygon directions

MRC — Fri, 12 Jul 2019 02:11:53 GMT

Hello everyone,

i have a problem, pls help me solve...

i have two shaple files : 1. line - the streets

2. polygon- the polygon of the parcel of land

then i want to calculator of the dicrections of the polygon following the street line, the result i expert is list of the table show : N- if the direction of the polygon is north, W -if the direction of polygon is west , NW - north - west , S is it south and ....

i have attached two file shp for you references ... pls help me

Sorry for my bad english,

thank you...

if you aren't understand my problem just tell me explain more....

Re: Calculator of polygon directions

MRC — Fri, 12 Jul 2019 02:19:28 GMT

i attached more information about the directions..

Re: Calculator of polygon directions

MRC — Fri, 12 Jul 2019 09:30:32 GMT

please help me? anybody ?

Re: Calculator of polygon directions

MRC — Tue, 16 Jul 2019 04:26:48 GMT

...

Re: Calculator of polygon directions

RichardFairhurst — Tue, 16 Jul 2019 08:59:06 GMT

Based on your map example, it is an ideal situation where the parcel is rectangular. If every parcel was rectangular and at the exact tangent angle to the street, the easiest method would be to create linear referenced routes with your centerlines. Then use Feature to Point with the inside option to extract the centroid of the parcel. Then you can use the Locate Features Along Routes tool to get the measure and distance of the point along the centerline with an adequate search radius. I usually get all events for all centerlines within the radius and eliminate events that have an address street name that does not match the centerline name. I summarize the point on the parcel field to get a count of events for each parcel to determine if more than one event was created along a curve in the centerline, since technically all points along a tangent radial curve to the centroid are valid events, and manually eliminate all but one of those points. An event layer can be created which displays an angle field and that layer can be exported to a real point feature class that will store the angle field values permanently. From the angle you can determine the compass bearing of the tangent line from the parcel centroid point to the centerline. You can also tell if the parcel is on the left or right hand side of the centerline, because the distance values are positive or negative depending on which side of the line the point is on.

You can join the point to the parcel using the parcel number and calculate over the angle or compass direction.

Re: Calculator of polygon directions

JohannesBierer — Tue, 16 Jul 2019 09:29:33 GMT

Isn't it possible to use the near tool and calculate the near angle?

Re: Calculator of polygon directions

MRC — Tue, 16 Jul 2019 09:45:29 GMT

Thanks for your help @Richard

Unfortunately the parcel has a lot of shapes, not only rectangular but also have other shapes as you can see of my folder attachments, i couldn't calculator correctly the directions, My idea is write code python for calculator this problems, but my ability to write code is very poor... when im write result show not like me expert ..

could you give me an advise ...

The most difficult thing in this problem is that I cannot determine the direction of the parcel following the directions of the streets line..

If you can write code to help me, I am very grateful to you!

Again Thank you very much, wish you good health....

Re: Calculator of polygon directions

MRC — Tue, 16 Jul 2019 10:01:55 GMT

if you use the near tool to calculator,The result is that there will be many cases that are wrong,in my opinion i think it isn't possible.. i tried. ..

Re: Calculator of polygon directions

RichardFairhurst — Tue, 16 Jul 2019 15:18:06 GMT

No code exists, except for the ideal situation. While I can imagine some other methods, there is no way to know for sure what the parcel shape is without deep learning AI that I don't know how to write. All I could do is solve the problem for the ideal situation and then come up with a way to determine if it worked and try another set of geoprocessing steps for the parcels that failed. That probably would involve weeks of trial and error to come up with a 95% to 99% solution. I don't have the time to do that. Python is not the issue, the issue is coming up with the sequence of geoprocessing steps and validation checks at each stage to identify the parcels that passed and failed the previous steps you applied and coming up with an alternative geoprocessing set of steps that fits the majority of the parcels that failed. No one knows all of those steps and validation checks for this problem. Python only makes it easier to apply the steps in the right order in a repeatable manner once you figure them out, but it cannot figure out what those steps are for you (without AI).

AI will only get to a 90% to 99% solution at best as well, although the benefit is that it does the learning process and applies the solutions much quicker if you can come up with a way to train it. However, no set of automated logical solutions will ever reach 100%. 100% can only be achieved at some point by coming up with some way to identify candidates that you suspect didn't get solved by all of the steps you have already applied and inspecting and manually solving each one at some point, and even then somethings won't get caught.

Re: Calculator of polygon directions

MRC — Wed, 17 Jul 2019 01:45:37 GMT

You're right @Richard

With python code when built up, I could accept the error of 90-95%, the remaining 5-10% I will have to handle the hand to correct. I realized that it is very difficult to do this problem correctly with too few conditions, as you say i also think there is no technology AI can identify the direction of the parcel, If you could help me write a short code for cases that can only be solved 90%, I believe I can solve the remaining 10%, thank you very much for taking the time for me.

I also know that you have very little time, but if you could take some time to help me, I really thank you very much...

Re: Calculator of polygon directions

MRC — Thu, 18 Jul 2019 02:25:18 GMT

Could you help me solve this? thank you

Re: Calculator of polygon directions

MRC — Fri, 19 Jul 2019 06:53:24 GMT

anyone coder here?

Re: Calculator of polygon directions

JoshuaBixby — Fri, 19 Jul 2019 16:36:28 GMT

As a starting point, which might just be good enough since you aren't looking for the 100% process, use Minimum Bounding Geometry—Help | ArcGIS Desktop with RECTANGLE_BY_WIDTH, and include the MBG geometry fields.

Re: Calculator of polygon directions

RichardFairhurst — Fri, 19 Jul 2019 17:09:33 GMT

I agree with Joshua that the Minimum Bounding Geometry tool may be a good starting point for analyzing your parcels, since you could compare the area of the parcel to the area of the minimum bounding geometry to separate parcels that are basically rectangular from parcels that are not. Most likely it will be much easier to develop a process that can be successfully validated for parcels that are rectangular than for parcels that are more complex. Separating parcels into different classes like rectangular and non-rectangular is critical to being able to build up a multi-tiered automated process that might ultimately be capable of handling the majority of parcels correctly.

Re: Calculator of polygon directions

MRC — Tue, 23 Jul 2019 08:13:47 GMT

Could you show me your direction to do it?

I tried but the results are still not very accurate ...

Thank for your help @Joshua

Re: Calculator of polygon directions

DanPatterson_Retired — Tue, 23 Jul 2019 09:01:52 GMT

perhaps if you show your results, it would assist in assessing what, if any, isn't good.

It may be the case that you have a problem that has no simple solution, or one with several solutions depending on certain conditions.

Problems are not always solved with simple solutions, this may be an 'abstraction' type problem and your model as to what you expect to happen isn't well supported by your data

Re: Calculator of polygon directions

JoshuaBixby — Tue, 23 Jul 2019 14:45:00 GMT

I agree with Dan, you need to show some examples. When I ran the tool on your sample data set, the results looked quite good.

Re: Calculator of polygon directions

MRC — Wed, 24 Jul 2019 10:17:21 GMT

Thank for your help Dan Patterson‌ , i have attached two shp files which have the results for your request...

The above results are mostly true with 90% accuracy.

Could you give me an advise?

Based on the old results, my calculation is

- Create point of land plot

- Use near tool and Calculate the angle from the point just created to the road

- Use python code to switch from angle to direction ....

Re: Calculator of polygon directions

MRC — Wed, 24 Jul 2019 10:20:22 GMT

My file is attached above with the name question_new_24-07-2019

Re: Calculator of polygon directions

MRC — Wed, 24 Jul 2019 10:21:23 GMT

Could you guide me on your calculation?