I need your help please for generating polygons from set of points

[kaderb]

Hello,

 

I am working on a project that requires that I automatically generate polygons to approximate the boundaries of some districts because our country does not have these informartions. The idea I had was to generate these boundaries from the distances of the point groups belonging to each polygon. I attach the diagram below in order to illustrate my ask.

 

 

I only have the coordinates of the points Ai to Gi. All Ai points belong to the polygon A, all points Bi to the polygon B, etc. I do not have any data space allowing me to create polygons A to B. I can be content with a realistic approximation, however. The idea then is to get the boundaries between these polygons, knowing only the coordinates of the points Ai - Gi and knowing that each point Ai belongs to the set A, and so on.

 

I have no idea how to proceed. Maybe this has already been processed. Would it be possible, please, to give me guidance on how or where to find a similar job if he had be done.

 

Thanking you a lot in advance.

 

Best regards

[yousef2233]

Hi,

one simple way is using voronoi polygons

if you have arcmap installed, this is the procedure :

open Arctoolbox > Analysis Tools > Proximity > Creating Thiessen Polygons

set your points as Input Features - dont forget to set Output Fields to ALL

 

now, u have voronoi polygons for each point, next step is dissolving the little polygons to big one according to, A,B,C,D,...

Arctoolbox > Data Management Tools > Genralization > Dissolve

set voronoi polygon from last step for Input Features - this one is important : Dissolve Field> select field which is contains A,B,C, ....

* if you dont have it, you must create it from A1,A,2,...B1, B2,....

before going into dissolve, create a new field and calculate it with Left(values,1), this new field and the calculate formula extracts the first left letter. it will extract A from Ai

good luck

[msig0000]

Hi,

one simple way is using voronoi polygons

if you have arcmap installed, this is the procedure :

open Arctoolbox > Analysis Tools > Proximity > Creating Thiessen Polygons

set your points as Input Features - dont forget to set Output Fields to ALL

 

now, u have voronoi polygons for each point, next step is dissolving the little polygons to big one according to, A,B,C,D,...

Arctoolbox > Data Management Tools > Genralization > Dissolve

set voronoi polygon from last step for Input Features - this one is important : Dissolve Field> select field which is contains A,B,C, ....

* if you dont have it, you must create it from A1,A,2,...B1, B2,....

before going into dissolve, create a new field and calculate it with Left(values,1), this new field and the calculate formula extracts the first left letter. it will extract A from Ai

good luck

 

Could you tell what is difference if  i follow the following model..........

 

Split by attribute> Minimum bounding geometry>Union (all separate bounding geometries)..

[yousef2233]

as i know, split by attributes, splits a feature class into multiple featureclasses according to unique values. the minimum bounding geometry tool makes a boundary around each featureclass. this is good but after using union tool, there will be gaps between the regions. how could you fill those gaps and fixing possible overlaps?

[intertronic]

Read the ebook :

 

"The ESRI Guide to GIS Analysis" Volume 2

 

http://www.gisarea.com/topic/4918-the-esris-guide-to-gis-analysis-volume-2-spatal-measurements-and-statistics/