R/f.intersect.area.R

In constrainedKriging: Constrained, Covariance-Matching Constrained and Universal Point or Block Kriging

f.intersect.area <- function( polygons, gpc.pixel)

### purpose: function returns a list with the intersect area between
###          the pixels and the polygons
### arguments:
###            polygons = polygon list
###            gpc.pixel = gpc.poly object of the pixel
###
### author: ch.hofer
###  date: 27.2.2007
{
t.intersect.area.list <- lapply( gpc.pixel,
                                function( gpc.pixel, polygons){

                                    ### old return( area.poly( intersect( gpc.pixel, polygons ) ) )
                                    area <- area.poly( intersect( gpc.pixel, polygons ) )
                                    return( area )
                                },
                                polygons
			    )
return( as.vector( t.intersect.area.list, mode = "numeric"))
}