Jul
The warning about kriging small blocks is about
"small" relative to the sampling density. For example,
less than about one-third of the grid spacing.
The warning is the same as the one about 'point'
kriging (mapping) The map is too smooth - or, at
least, a lot smoother than the real surface
Title: Message
Hello
Syed,
I
was hoping a reply from you :)
I
didn't think about the problematic of anisotropy and the potential use
of ratios of fractal dimensions. It might be worth some further investigation.
The
physical meaning of fractals derived from directional variograms i
Hi All,
I am at the beginning of modelling fluvial sand
channels using subsurface well data (logs &cores). I would appreciate if
you could send me some tips on the optimum way to do this using object
modelling and indicator techniques. Are there any published work dealing with
the ge
Object-based models where first applied to fluvial channels, becouse the
"simplicity" of their geometries, there is a lot of papers published regarding
this subject:
Journel, A. G., R. Gundeso, E. Gringarten, and T. Yao. 1998. Stochastic
modelling of a fluvial reservoir: a comparative review of
Nicolau
I was talking about kriging before cutoff is applied.
If the cutoff is applied to the block estimates my
comments stand. If you aply the cutoff to your data
first and then krige, you get the opposite problem,
because you will over-estimate every value and
under-estimate the tonnage.
My po
Dear Mike.
In point pattern analysis, your sample is supposed to
be a homogeneous thinning of a more global underlying
point process, and is therefore expected to share same
characteristics.
Usually Monte Carlo simulations are involved to test
null hypothesis. The less point you have the less
rob
Feng Liu wrote:
Hi, Dear List:
I am trying to use Gstat to do Gaussian
Conditional Simulation on my soil C content data. I got 3 questions as
following:
1. If I use "set nsim=100"
to do 100 times simulation, does the simulations follow a single random
path or they w
Hi
I think the discussion below is missing some key points:
1. If the individual block estimates are to be used for actual selection at
the time of mining, then conditional bias will impact the predicted
recoveries and should be minimized.
2. However, if the block model is to be used for long term
Ed
I would differ from your explanation on one point.
If you are merely declaring a mineral resource, i.e.
mineral in the ground, then the conditional bias may
not be relevant at the "pre feasibility" stage.
However, as soon as you introduce any economic or
technical parameters which entail sel
Gregoire,
To be honest I have never attempted this, although as you said the angular tolerance, bandwidth, and lag tolerance will ultimately determine whether the directional fractal dimensions can be averaged to give an "omnidirectional" dimension, D. I would argue that two directional variogram
Hi Isabel
If you go to www.isaaks.com and click on "Otherstuff", you will find an
example where the block estimates are conditionally biased (rather
severely), but the grade tonnage curves are right on the money. Perhaps this
will help clear the confusion. Ed
-Original Message-
From: Isob
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