suppressMessages(library( fields))

#  colorado climate data 
data(COmonthlyMet)

x<- CO.loc
y<- CO.tmin.MAM.climate
elev<- CO.elev
good<- !is.na( y)
x<- x[good,]
y<- y[good]
elev<- elev[good]

NGRID <- 50 
# get elevations on a grid (will use these later) 
COGrid<- fields.x.to.grid( x, nx=NGRID, ny=NGRID)
COGridPoints<- make.surface.grid( COGrid)
data( RMelevation)
COElevGrid<- interp.surface( RMelevation, COGridPoints )



# take a look at the data
quilt.plot( x, y) 
US( add=TRUE)

plot( elev, y)

plot( x[,2], y)