variogram maps / newbie
Facundo, your explenation is very clear. When I once tried, In addition I found different numbers of point pairs across the two packages; this could be due to classification of point pairs with distances exactly on the bin boundary, but I didn't come to a conclusive feeling about it, back then. -- Edzer
Facundo Mu?oz wrote:
Hi Pedro,
perhaps if you could paste some sample code, we could talk about
something more concrete...
I understand that you were able to plot empirical variograms using both
variog (geoR) and variogram (gstat).
In both of them you control the maximum distance:
in geoR: using max.dist, or uvec which also allows to define the bins
in gstat : with cutoff
and the binning: uvec (geoR) and width (gstat).
In despite of this, they will not plot the same empirical variograms
even if you define the same bins and maximum distance, since variog
(geoR) places the estimates exactly at the bins limits, while variogram
(gstat) calculates the mean of the distances of the pairs of
observations used for each estimate, and places the estimate at that
precise distance. (Ajjj, i'm sure it can be said better)
In sum: even if you manage to make them calculate the same estimates
with the same pairs of observations each, you will have the same
estimates but located at (more or less slightly) different ordinates.
Reagards
Facundo.-
Pedro Mardones escribi?:
Dear all;
Does anyone knows how to obtain a variogram map using the package geoR?
I was able to obtain these plots using the gstat package but the
results form the variog function are different to those from variogram
function in gstat (I guess that has something to do with the bin and
maximum distance but not sure)
Suggestions will be appreciated
PM
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