In geometry, the centroid, geometric center, or barycenter of a plane figure or two-dimensional shape X is the intersection of all straight lines that divide X into two parts of equal moment about the line. Informally, it is the "average" (arithmetic mean) of all points of X. The definition extends ...
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Calculating Centroid of add shaped polygons [duplicate]
I need to calculate the centroid so that it is still contained in the related polygon. I have used the centroid tool in ftools and the centroid maker and have the same results as shown below.
Is ...
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assign and move centroids to their polygons
I m using QGIS 1.8 Lisboa. After calculating the centroids from a polygon shapefile, if some of them lie outside the polygon outlines, I'd like to move them on the polygon they came from. The ...
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OpenLayers move each vector feature of layer by constant pixels away from center
I am stuffing a lot of features, each from a different layer, onto exactly the same point, so the visual result is somewhat confusing and it is necessary that some graphics have some offset of ...
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3answers
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How to determine the centroid of polygons?
I have a polygon vector and I want to quickly attain the centroid of this polygon for insertion in a text document. I am working with QGIS. I searched through other questions and although some are ...
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Centroid of the equator and a point
Suppose I already have a way to compute the centroids of different geometry types:
Points (arithmetic mean of Cartesian coordinates).
Linestrings (polylines) (weighted mean of segment mid-points in ...
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How to calculate polygon centroids in R (for non-contiguous shapes)
I've spent a little while figuring out the answer to this question.
It's not immediately obvious from a Google search, so thought it may useful to post the answer on here. There is also an additional ...
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2answers
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Calculating a spherical polygon centroid
I'd like a general way to calculate centroids for polygons on a sphere.
So far, the best online reference appears to be:
Tools for Graphics and Shapes by Jeff Jenness.
The method described ...
2
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1answer
368 views
How to take polygon centroid in Postgis
I have table with column name,Latitude and Longitude.I want to update this with polygon name and its centroid latitude longitude.I know there is a function in postgis st_centroid(geometry). But I want ...
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Is it possible to extract Coordinates of Polygon Centroid in QGIS?
I have created polygon centroids using one of the "Geometry Tools" but I would like to extract the actual coordinates into Excel for further work. Is this possible?
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table of polygon centroids
Given a polygon layer, census tracts, how can I generate a table of centroid coordinates in QGIS, or add columns with the centroid coordinates or generate a new layer of polygon centroid points?
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python error when using polygon centroid tool [closed]
When I use the "Polygon Centroid" tool -- to fix labeling features on a shapefile...i get this "Python Error" with a bunch of coding I do not understand in a text box. Afterward QGIS 1.7 shuts down on ...
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ArcGIS 10 — Polygon Centroid Options and Appropriateness (FeatureToPoint, Labels, etc)
I've found a couple of other Stack Exchange questions related to this, but just like the ArcGIS online help, they were not satisfying. For instance,
How does ArcGIS calculate the "inside" ...
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Find polygon centroid with Python
I'm using ArcGIS 9.3 to find centroid of some polygon features. I'd like to do this in Python, but so far I can only find solutions with VBA. Can anyone provide some leads here?
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How to find polygons centroids? [duplicate]
Possible Duplicate:
Get list of coordinates for points in a layer?
Sorry for another basic question - my map is almost done but now my boss wants me to enter new outbreaks (that we don't ...
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How to find the center of geometry of an object?
Well it might be a simple question. Given a set of 2D or 3D points, the question is:
How to find the center of geometry of an object?
According to the following figure, the center of geometry ...
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How to get the coordinates in Lat/long from a point layer?
Sorry for asking this basic question, but I couldn't get the solution from the previous answers.
I need to extract the Lat/long coordinates of the centroids of districts.
My QGIS project SCR and the ...
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2answers
870 views
Formula to get polygon centroid
I need to compute the centroid position of an irregular polygon with lat and lon coordinates in Java.
Which formula should I use to correctly compute a centroid?
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3answers
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How to place multiple symbols on one polygon centroid?
I am using QGIS for visualizing the health conditions of elderly living in an old age home, some of the elderly have multiple medical device with them and I want to show them on the map.
Suppose I ...
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How does ArcGIS calculate the “inside” point for “Feature to Point”
Let me back up and say that from what I understand there are two common ways to calculate the centroid of a polygon in ArcGIS:
Using Calculate Geometry on fields within the attribute table of the ...
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1answer
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How to force QGIS Centroid Fill inside the Polygon?
I would like to use a centroid fill to enable me to place a letter inside a polygon. The advantage of using a centroid fill is that it also shows up in a legend, whereas labelling the layer would mean ...
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How to create point labels from midpoints of road polylines in QGIS?
Heres what i want to achieve: i have a roading polyline layer (singlepart ie has several features per road, grouped by an id field), and i want to (after merging the parts) find the mid point of the ...
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3answers
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How can I calculate the center point inside a polygon in ArcGIS 9.3?
I'm using the JavaScript API 1.6 on ArcGIS 9.3. I have a polygon geometry in an ArcGIS map, and I'm trying to find a way to get the point that lies in the exact center of the geometry. What is the ...
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2answers
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How do I calculate a weighted centroid with respect to a raster, e.g. population weighted centroid
In ArcGIS 10.0, how do I calculate the weighted centroid of a collection of polygons, where I want the weight to be a raster layer. In particular I am using a raster of population counts and would ...
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6answers
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Is it possible to query a MySQL database using the results from map.getBounds() with Google Maps API v3?
I have a MySQL database that contains a large number of polygons, one for each district on a map. They are all quite complicated and it's unrealistic to simply load them all at once. I've looked into ...
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1answer
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find the centroid of a cluster of points
While searching the web, solutions for finding centroids of polygons come up rather often. What I'm interested in is finding a centroid of a cluster of points. A weighted mean of sorts. I would ...
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Where can I obtain an up-to-date list of US ZIP Codes with Latitude and Longitude Geocodes?
NOTE: This began as a question on Stack Overflow, which has subsequently been closed. I also noticed a similar question about Most Up-To-Date Source for US Zip Code Boundaries, but I believe this ...
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Misalignment when generating centroids with Qgis
I was wondering if anyone could shed a light on why this behavior is happening in QGIS ?
I'm pretty confident that the issue here is not due to "centroids within polygon"
Edit
Added a detailed ...
