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12

If you are interested in an implementation look at jsts a Javascript implementation of the much used Java Topology Suite library -- depending on whether you prefer reading Javascript or Java, I suppose. A general idea of how the algorithm works. For points, it is trivial, you simply buffer them by a given radius. If you have multiple points, you will have ...


6

You're almost there! Using the standard buffer tool, enter your desired distance as a negative value, then set the line_side parameter to OUTSIDE_ONLY. This will generate areas inside of each polygon, giving the nice look of country borders on a political map when combined with a transparency setting: Taken from my other answer


6

Starting in ArcGIS 10.0, running the Buffer tool on a point or line feature class with a geographic coordinate system (e.g. WGS84, NAD83) results in geodesic buffers that are completely free of distortion. That is probably what happened here, except that your data frame's coordinate system is distorting the area. From the help page (emphasis mine): You ...


6

Here's a script I put together. The script uses your point and your line feature class, and outputs a new line feature class of line features as desired. The basic steps: Iterate through points Create a buffer around each point Create East-West line from each point. This will be used to slice your buffer in half Create point north of each input point. This ...


5

Would something like this work for you? I'm assuming that the right of way area includes both sides of the road and that you know the length of the road you are measuring. // Use the same sq distance measurement as your buffer, a sq meter area uses a buffer in meters var_area = 500 road_length = 100 buffer_distance = (var_area/road_length)/2 ...


4

I think you want to exclude the intersection of the buffer in the where clause. WITH subq AS ( SELECT p.id, p.name, unnest(ARRAY(SELECT q.name FROM w_point q WHERE p.id != q.id AND NOT ST_Intersects(q.geom, ST_Buffer(p.geom, 0.1)) ORDER BY ST_Buffer(p.geom, 0.1) <#> q.geom LIMIT 5) ) as name FROM w_point p ) SELECT ...


4

Yes, you can have your buffer in meters just by adding Meters in your field 'BUFFER' like 1000 Meters, 250 Meters.. and so on. This is documented on ArcGIS resources - Buffer (Analysis) Here is the snippet from site stating this capability. If a field from the Input Features is used to obtain buffer distances, the field's values can be either a ...


4

Running the buffer tool will create a second polygon offset the distance you specify from the first. Corners are radiused by default, no need to crop.


4

Can you work with arcpy in Python a little bit? You could use some script to generate these zones in specific direction. I made some similar few weeks ago, I could post part of my script to help you. import arcpy, math, gc # Workspace, overwrite arcpy.env.workspace = r"YOUR_WORKSPACE" arcpy.env.overwriteOutput = True # INPUTS objects_input = "objects.shp" ...


3

Completely edited my previous answer. First of all, you're dealing with @52k points so whenever you're running an analysis with this amount of data, chances are QGIS looks frozen but more often than not it is still processing (can check this with Task Manager and CPU usage). To start, we need to filter out all the unnecessary points we don't want so I ...


3

You have to use a projected CRS like UTM (for your part of the world) to get real circles and meters as units. Please do not use Google/Web Mercator, it does not use real meters as units (only at the aequator).


3

If you use the v.buffer tool in the Grass Commands toolsets, you can make a flat buffer. There there are two choice boxes If you have Make outside corners straight set to No, and Don't make caps at the ends of polylines as Yes, the result should be similar to the ArcMap straight edge buffer. The following are the 3 combinations of the above two ...


3

As a shapefile FIDs' are contiguous and 0 based, you can use that to your advantage: import sys, os, arcpy InFC = sys.argv[1] # must be a shape file OutFC = sys.argv[2] # change as appropriate DivisorSize = 1000 BufferDistance = 100 TempDir = os.environ.get("Temp") MaxFeat = int(arcpy.GetCount_management(InFC).getOutput(0)) StepRange = ...


3

This question is a year old but this alternate solution may be helpful to others. If you are using the Popup class you can set the Popup to a global variable so that you can set it not to show the window while updating. To prevent getting the "No information available" window, just set visibleWhenEmpty to false and hideDelay to 0: var popup = new ...


3

This really depends on a number of factors. Are you talking about a large number of features? Do you have 100 neighborhoods and 1000 point locations, or a thousand times that number? Is your precision requirement high enough that you'll need to take Great Circle calculations into account? At less than 10 miles the error will be around 10-30 meters, ...


3

Super simple. Change side type to 'Outside Only' and you got it:


3

As you have already mentioned in your comment Rudolf, you may have performed a Query which only filters out features, it does not perform any analytics. The Intersect will 'cut' out features which intersect one another and outputs the results in a new layer. The Intersect function can be found in: Vector > Geoprocessing Tools > Intersect


3

Ensure that your polygons have an area attribute separate from the one that is/may be automatically updated by the software when the shape is edited. Intersect your buffer and polygon layer. In the resulting layer, open the attribute table. If there is a new/correct area field in the same units as the original area field from step 1 you can use that - ...


3

Have you tried to write the different distances in a python list : [356.8,792] as describe in the ressources : http://resources.arcgis.com/en/help/main/10.1/index.html#//00080000001p000000


3

ST_Collect is probably not the function you are looking for, as this simply combines geometries into a geometry collection of some type, and does not actually union/dissolve them. ST_Union, on the other hand, does dissolve overlaps, and assuming polygonal input (which is most probable in conjunction with ST_Buffer and an input table called point), and ...


3

To do this I would use two tools: Intersect (Analysis): Computes a geometric intersection of the input features. Features or portions of features which overlap in all layers and/or feature classes will be written to the output feature class. then Summary Statistics (Analysis) Calculates summary statistics for field(s) in a table.


3

If you are using ArcMap, the Spatial Join tool with the One to One option will add summaries of the Points to the Buffer shapes if the Buffers are the Target. You can set one of the Point fields to be a Count field. Other fields can be summarized with Sum, Min, Max, Mean, etc values. If you need a list of values use the Join option and change the output ...


3

As one can see from the picture the task has a solution for shapes equal to their own convex hull. If it is not the case, the position of point and 'un-convexness' of polygon might create artefacts. Output can be slightly improved by using minimum spanning tree of the points, but it's cheating and too much for today. import arcpy, traceback, os, sys from ...


3

As you only have 2 buffer distances, you could do this in 2 easy manual steps (if you had more buffer distances I would recommend using the code from Polygeo). Step 1: Use the "Buffer" tool to create a 6 km buffer around all your points. Make sure you set Dissolve to "None" Step 2: Use the "Multiple Ring Buffer" tool to create a 6km buffer around the ...


2

Now possible with the Multi Ring Buffer: https://plugins.qgis.org/plugins/Multi_Ring_Buffer/ In version 0.1 it only works on the layer that is selected in the TOC when you launch the tool but feature requests can be posted to the issue tracker: https://github.com/HeikkiVesanto/QGIS_Multi_Ring_Buffer/issues


2

I agree with @Chris W that it is unusual that the buffer operation is running out of memory. Regardless, there are a few routes to take. First, run the buffer tool as a 64-bit process. Second, try the attached script. The general workflow: Create fishnet of the same extent as the input points Iterate through the fishnet features and select the points ...


2

the quick and dirty solution is to use a temporary feature class (using copy with your layer or select). You will then have new FID's and you can iteratively select bunches of 1000 points for the buffer tool. A better solution (but a bit longer to write), is to use arcpy.da.searchcursor for reading your points, and arcpy.da.insertcursor for writing the ...


2

I was just looking for the same answer myself and while my answer is not 'official', it's based on my interpretation of this Training Manual entry I found: http://docs.qgis.org/2.2/en/docs/training_manual/answers/answers.html#basic-distance-from-high-schools I think the above illustrates the buffer segments quite well. My answer is therefore... The ...


2

You can select by location the features in the blue circle, e.g. using the rules "touch the boundary of" your buffer, then select from the selected feature using "within" your buffer. In your case, you could also select based on the length (they are very small compared with other lines), but the first method is safer. Once this is done, you can either ...


2

Add the Editor toolbar and start an edit session. Highlight a feature on the map and click on the Editor menu. Click on Buffer and set the buffer distance. If you need something else, the easiest way would probably be to create a Python addin. It's kind of hard to figure out exactly what you're trying to do from your question.



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