This function selects an IRS of an area resource.
irsarea(shapefilename = NULL, areaframe, samplesize = 100,
SiteBegin = 1, maxtry = 1000)
Name of the input shapefile. If shapefilename equals NULL, then the shapefile or shapefiles in the working directory are used. The default is NULL.
Data frame containing id, mdcaty, area, and mdm.
Number of points to select in the sample. The default is 100.
First number to start siteID numbering. The default is 1.
Maximum number of iterations for randomly generating a point within the frame to select a site when type.frame equals "area". The default is 1000.
data frame of sample points containing: siteID, id, x, y, mdcaty, and weight.
getRecordIDs
C function to obtain the shapefile record IDs for records from which sample points will be selected
getShapeBox
C function to obtain the shapefile minimum and maximum values for the x and y coordinates
pointInPolygonFile
C function to determine the polygon IDs and the probability values associated with a set of point, where polygons are specified by a shapefile