https://github.com/cran/fields
Tip revision: 4917938f752d85678f5f771f30ba6605cf754d6c authored by Douglas Nychka on 05 July 2022, 20:40:02 UTC
version 14.0
version 14.0
Tip revision: 4917938
as.surface.R
#
# fields is a package for analysis of spatial data written for
# the R software environment.
# Copyright (C) 2021 Colorado School of Mines
# 1500 Illinois St., Golden, CO 80401
# Contact: Douglas Nychka, douglasnychka@gmail.edu,
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with the R software environment if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
# or see http://www.r-project.org/Licenses/GPL-2
##END HEADER
"as.surface" <- function(obj, z, location=NULL, order.variables = "xy") {
#
if (is.list(obj)) {
grid.list <- obj
}
if (is.matrix(obj)) {
grid.list <- attr(obj, "grid.list")
}
#
# OK now have a grid, parse this to figure
# nx and ny the x and y sequences and extract names
#
hold <- parse.grid.list(grid.list, order.variables = "xy")
if( !is.null(location)){
# location is a logical or two column matrix of indices
# with the position of the z values
temp<- rep( NA, hold$ny*hold$nx)
temp[location]<- z
temp<- matrix( temp, ncol = hold$ny, nrow = hold$nx)
}
else{
if( length(c(z))!= hold$ny*hold$nx){
print( length(c(z)))
print( c(hold$ny*hold$nx))
stop("z does not match number of grid points")
}
temp<- matrix( z, ncol = hold$ny, nrow = hold$nx)
}
#
# note that coercing z to a matrix is just reformatting
# using the standard ordering.
#
# output list is all the grid stuff and the matrix z.
c(hold, list(z = temp) )
}