ptsinpoly _ function(x,y,xinf,yinf,xy){
  z _ .Fortran("ptsinpoly",
	   n.check = as.integer(length(x)),
	   as.single(x),
	   as.single(y),
	   as.single(xinf),
	   as.single(yinf),
	   n.vert = as.integer(length(xy)/2),
	   as.single(xy),
	   iotmsg = as.integer(0),
	   inpoly = as.integer(rep(0,length(x)))
	   )
  z$inpoly
}