Problem with "autoKrige" Function

Hi everybody. I?m trying to explore kriging performance for some runoff
interpolations and I?m using "autoKrige" function from package "automap".
Following the examples for function I?ve run Ordinary Kriging and Universal
Kriging, but when I try to run ?"Drift, Regression or Universal Kriging"
with variables different from "x" and "y" I get this error:

"Error en eval(expr, envir, enclos) : objeto 'Prec' no encontrado" (R is in
Spanish), which says that the object 'Prec' was not found. My code is:

X=read.csv("F:/Rancheria/EscPrecDEM.csv")
coordinates(X)=~x+y
Grid=read.table("F:/Rancheria/puntos_prediccion.txt")
coordinates(Grid)=~x+y

autoKrige(Anual~Prec+Altura, X, Grid)

I?ve tried renaming the variables to the same names of data "meuse", to
follow exactly the example of the function:

autoKrige(zinc~soil+ffreq, meuse, meuse.grid)

but I still getting the same error. If someone can help me with this I?ll be
so grateful. Thanks in advance.

--
Jaime Burbano Gir?n
Departamento de Ecolog?a y Territorio
Pontificia Universidad Javeriana
Bogot? - Colombia
(571) 3208320 Ext. 4836

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