Dear Prof. Clark
Here is the paper:
http://www.ansinet.org/fulltext/jas/jas581405-1407.pdf
Formula (4) is the weight factor.
King regards.
Behrang.
- Original Message -
From:
Isobel Clark
To: Behrang Kushavand
Cc: AI Geostats mailing list
Sent: Tuesday, February 28, 2
Hi Susan,
I would recommend the Stanford Geostatistical Modeling Software (S-GeMS)
that is public domain and that I use in all my short courses (some of your
colleagues have actually be trained by me). The software can be downloaded from
http://pangea.stanford.edu/~nremy/GEMS/
Cheers,
Pierre
Hello,
I have been using a modified version of VARFIT that is available on the
Computer and Geosciences website.
Pardo-Iguzquiza E: VARFIT: a Fortran-77 program for fitting variogram models by
weighted least squares. Computers and Geosciences 1999, 25:251-261.
I agree that choosing a set o
Ed I use the Cressie statistic to four significant figures as a guide in the interactive fitting, but generally end up using a visual judgement. It tracks as you drag the model around, so you can watch it change. I think the 'real' visual objective function is probably the perpendicular (to
Hi Chris,
It depends on the inference space you wish to work in.
If your hypothesis is justing testing for a difference in the population
means of the three survey extents (fields),
then any underlying autocorrelation in the population(s) is not really
problematic
- it is actually a bonus (i.e
Isobel Clark wrote:
Behrang
What weighting do you use in the weighted least squares?
Isobel
I have found choosing suitable weights always a frustrating
event. Cressie's weights, let's say N_h/[(gamma(h))^2], has
attractive properties, both intuitively and statistically. Here,
gamma(h) is t
Yikes!
I was working through
the tutorial for the Geostatistical Analyst Extension
when this email discussion popped up. Any recommendations for a “traditional geostatistics
software package”?
Thanks,
Susan
Susan
Hohner, Senior Geographer
Everglades Division, Mail Stop 4440
Behrang What weighting do you use in the weighted least squares? Isobel http://www.kriging.comBehrang Kushavand <[EMAIL PROTECTED]> wrote: hi,I have a software for Variogram AUTO Modeling (winvam) that works with gslib(GAMV.exe).First you must calculate experimental variogram (omni or dir
Dear all,
I have the same concerns with ArcGIS Geostatistical Analyst Extension
(v.9.1). I would use a traditional geostatistics software package
to fit the variogram models in a very traditional way, and input the parameters
to ArcGIS for kriging. It seems that ArcGIS has its own
Hi All It is difficult to have an automatic best fit semi-variogram until you define what you mean by "best fit". Noel Cressie's goodness of fit statistic goes a long way towards the ideal, but is very insensitive to changes in nugget effect and pretty insensitive to fairly large changes in the
Mach Nife wrote:
Hi,
I'm hunting for a software (freeware/openSource if
possible), that would help estimating the best
possible semivariogram curve in a non-interactive way.
As an example, ArcGis Geostatistical Analyst does a
pretty good job at this when we accept the defaults.
It does some aut
Hi,
I'm hunting for a software (freeware/openSource if
possible), that would help estimating the best
possible semivariogram curve in a non-interactive way.
As an example, ArcGis Geostatistical Analyst does a
pretty good job at this when we accept the defaults.
It does some automatic calculations
Chris,
How about using a "T-test" to test for similar sample means, or an
F-test to test for similar sample variance?
Regards,
Colin
-Original Message-
From: C.J.Banks [mailto:[EMAIL PROTECTED]
Sent: 28 February 2006 14:26
To: ai-geostats
Subject: [ai-geostats] Comparison of sample ar
Dear All
I have sampled three rectangular fields within a larger area and measured a
variable of interest at a lot of points in each of these fields. Values were
taken from all over each of the sampled fields but are not necessarily over a
systematic grid. I am interested in testing whether the
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