irsarea {psurvey.design} | R Documentation |
This function selects an independent random sample (IRS) of an area resource.
irsarea(src.frame="shapefile", shapefilename=NULL, xy.frame, areaframe, samplesize=100, SiteBegin=1, maxtry=1000)
src.frame |
source of the frame, which equals "shapefile" if frame is to be read from a shapefile and otherwise is equal to NULL. The default is "shapefile". |
shapefilename |
name of the input shapefile. If src.frame equal "shapefile" and shapefilename equals NULL, then the shapefile or shapefiles in the currrent directory are used. The default is NULL. |
xy.frame |
name of the data structure containing xy-coordinates for elements in the frame, where format depends on type.frame. If src.frame equals "shapefile", then equal to NULL. |
areaframe |
a data frame containing id, mdcaty and mdm. |
samplesize |
number of points to select in the sample. The default is 100. |
SiteBegin |
number to use for first site in the design. The default is 1. |
maxtry |
maximum number of iterations for randomly generating a point The default is 1000. |
A data frame of IRS sample points containing: SiteID, id, x, y, mdcaty, and weight.
Tom Kincaid Kincaid.Tom@epa.gov