| get.arcdata {RArcInfo} | R Documentation |
This function reads and imports into R the contents of an arcs definition file.
get.arcdata(infodir, coverage, filename="arc.adf")
infodir |
Directory where there is a file called arc.dat (usually it is called 'info'). |
coverage |
The name of the coverage we want to work with. |
filename |
The name of the file in the coverage directory that stores the data. By default, it is called 'arc.dat'. |
This function returns a list with two elements. The first one is a data frame containing the next fields (by columns):
ArcID |
A number that identifies this arc. |
ArcUserID |
I don't know what this exactly means. Please, remind me to fix this. |
FromNode |
The node where the arc begins. |
ToNode |
The node where the arc finishes. |
LeftPoly |
The number of the polygon that is to the left of the arc. |
RightPoly |
The number of the polygon that is to the right of the arc. |
NVertices |
The number of vertices the arc has. |
The second element is a list that stores the vertices of the arc. So, each element
in this list is also a list of two arrays: the first for the X coordinates
and the secod for the Y coordinates.
More information about this kind of data can be found at http://pages.infinit.net/danmo/e00/docs/v7_bin_cover.html.