Contents
How to calculate the centroid of a feature?
What you want for computing the centroid as the centre-of-mass of a feature is the gCentroid function from the rgeos package. Doing help.search (“centroid”) will have found this.
How to get data frame with polygons ID and centroid?
I have a polygon shapefile (downloadable here) from which I want to create a data.frame with 3 columns containing: From this answer here, I know it its quite easy to get this information as a Formal Class SpatialPoints object. And when I convert this object to a data.frame I loose the id information. Any idea on how to keep the id info?
How to calculate polygon centroids in are ( for non contiguous shapes )?
Doing help.search (“centroid”) will have found this. should show the difference, and be the same as the Qgis centroids. here is an approach using sf. As I demonstrate, results from sf::st_centroid and rgeos::gCentroid are the same.
Where are cents ( blue ) and centroids are identical centroids?
Where cents (blue) and centroids (red) are identical centroids (this should plot should appear after you’ve run the code): So far so good. But when you calculate polygon centroids in QGIS (menu: Vector | Geometry | Polygon Centroids ), there are slightly different results for non-contiguous polygons:
How to calculate polygon centroids for non-contiguous shapes?
So far so good. But when you calculate polygon centroids in QGIS (menu: Vector | Geometry | Polygon Centroids ), there are slightly different results for non-contiguous polygons: Firstly, I can’t find any documentation that says that coordinates or getSpPPolygonsLabptSlots returns the centre-of-mass centroid.
How to find the center of gravity from a datum?
Method 3 Find the Center of Gravity. The center of gravity is 9.08 feet from the datum, or measured 9.08 feet from the end of the left side of the see-saw, which is where the datum was placed.
How to calculate centre of mass in R?
Firstly, I can’t find any documentation that says that coordinates or getSpPPolygonsLabptSlots returns the centre-of-mass centroid. In fact the latter function now shows up as ‘Deprecated’ and should issue a warning.