about cross h scattergram

Hi guys,

I want to plot a h-scattergram between two attributes.

For univariate case, I use:

data(jura)
coordinates(jura.pred) = ~Xloc+Yloc
hscat <- hscat(Cd~1, jura.pred, c(0, 0.043, 0.214, 0.388, 0.616, 0.787, 

1.024))

in bivariate case, I used following script

data(jura)
coordinates(jura.pred) = ~Xloc+Yloc
hscat <- hscat(Cd~Ni, jura.pred, c(0, 0.043, 0.214, 0.388, 0.616, 0.787, 

1.024))

with ~Ni (secondary attribute) instead of ~1, but that gets me the same 
results of before.

any suggestions?

thanks

Cristiano