How to convert data frame to spatialpolygonsdataframe object?

How to convert data frame to spatialpolygonsdataframe object?

I have a data frame with a bunch of polygons, several points per polygon. How can I convert it to a SpatialPolygonsDataFrame object?

What happens if you merge two spatial DataFrames?

Never merge the data.frame associated with your Spatial*DataFrame object directly, as in the following snippet: If merge is passed two data.frames instead of a Spatial*DataFrame and a data.frame, it may jumble the order of rows in the output data, corrupting your data. That’s it!

How to merge tabular data with spatial data?

An attribute join combines tabular data with a Spatial* object by associating each observation in a table with a GIS object (a polygon, line, or point).

How to convert a spatialpolygon to a polygon?

When the Error: “row.names of data and Polygons IDs do not match” arise this solution seems to be helpful: rename IDs of the dataframe to match IDs of the polygons: I find the following solution generally works. Then use df as the second argument to the spatial dataframe conversion function:

How to create a plotorder for a polygon?

# ..@ plotOrder : int [1:140] 92 47 110 60 114 73 97 13 116 100 # Each polygon is itself a list with 5 slots (incl. all the vertice coordinates). # The ID slot is what ties the geometries and the attributes. # Note that like row.names, polygon IDs are character not integer.

How to create a list of polygons with attributes?

# Each polygon is itself a list with 5 slots (incl. all the vertice coordinates). # The ID slot is what ties the geometries and the attributes. # Note that like row.names, polygon IDs are character not integer. # Min. 1st Qu. Median Mean 3rd Qu. Max.

How to merge multiple polygons into one SPDF in R?

Using them in R, polygons become automatically SpatialPolygonsDataFrame (SPDF). I would like to merge them into single SPDF (as is super easy in ArcGis using Tool Merge ).

Why do I get non unique polygons ID slot values?

If you get a “non-unique Polygons ID slot values” error it means that the rownames of the objects are the same. To fix this you can use spChFIDs to change the rownames and associated slot relationships. Since the slots in the object use the rownames to associate the object, you cannot just change row.names in the @data slot.

How to create a spatial polygon in R?

Most people deal with SpatialPolygon files that have already been created and are read into R via a shapefile. In the next portion of this tutorial we’ll download a SpatialPolygonDataFrame that contains US State boundaries. We can get the data directly from within R using the getData function available in the raster package.

What’s the difference between spatial and spatial polygons?

SpatialPolygonsDataFrames have additional information associated with the polygon (e.g., site, year, individual, etc.) while SpatialPolygons contain only the spatial information (vertices) about the polygon. Let’s begin by creating a set spatial polygons layer from scratch.