Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-05 Thread Digby Millikan
Seumas, I was probably a bit misleading to say regression is not an estimation technique. The word regression meaning to revert back to the original, or find the underlying real equation for a set of data. Kriging is a form of what is called generalised linear regression which is one of the

Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-05 Thread Digby Millikan
For ore resource modelling I've used IDW on a highly skewed lognormally distributed deposit, where no variograms could be produced. With lognormally distributed data often found in ore resources, having a good variogram is important, to avoid large errors in kriging hence it may be preferential to

RE: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-04 Thread Pierre Goovaerts
: Tue 1/4/2005 3:06 PM To: ai-geostats@unil.ch Cc: Subject: RE: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW Just to get the group's opinion on this - When do you use IDW? When is it an advantageous technique

Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-04 Thread Edzer J. Pebesma
Darla Munroe wrote: Just to get the group's opinion on this - When do you use IDW? When is it an advantageous technique, or what purposes does it well serve? I use IDW to plot a smooth surface, fitted through the data points. This may serve as another spatial visualisation of the data; I see it

P.S. Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-03 Thread Gali Sirkis
When comparing kriging versus regression, I meant using linear regression between sparse and exhaustive datasets to interpolate the sparse one, since as Digbi Milligan pointed out in general case regression is not an estimation method. --- Gali Sirkis [EMAIL PROTECTED] wrote: Seumas, see

Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-03 Thread Volker Bahn
]; ai-geostats@unil.ch Sent: Monday, January 03, 2005 12:34 Subject: RE: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW | Hi Seumas: | | I thought I would throw my 2 cents in regarding a comparison between kriging | and linear regression. | | While some of the responses have hit a few

Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-02 Thread Gali Sirkis
Seumas, see few practical points that you may find useful: 1. kriging vs regression: a) kriging honors original data points, while regression does not b) kriging allows to account for anizotropy c) kriging allows to control the influence of the data points 2. Kriging versus other

Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-01 Thread Digby Millikan
Seumas Linear regression : not really an estimation technique for spatial data, though regression forms some of the basic theory for the derivation of kriging equations. Splines: not really an estimation technique, just

Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2005-01-01 Thread Digby Millikan
Seumas, Linear regression : not really an estimation technique for spatial data, though regression forms some of the basic theory for the derivation of kriging equations. Splines : not really an estimation technique, just

Re: [ai-geostats] Regression vs. Kriging vs. Simulation vs. IDW

2004-12-31 Thread Ben Fang
Hi: We had participated in AI-GEOSTATS SIC 2004 exercise in the past September. I think that several techniques (Kriging, regression, etc.) may have been used by different participants. It will be illuminating to read the final report of SIC 2004 when available. K.K. (Benjamin) Fang (We had