MATHEMATICS 574/ GEOGRAPHY AND REGIONAL DEVELOPMENT 574
Introduction to Geostatistics
(This page will updated from time to time)
Fall 2003
GEOSTATISTICS SOFTWARE
Without software and access to high speed computing, geostatistics would be of significantly
less interest. Three software packages will be used for class demonstrations. These include GEOEAS. VARIOWIN, R. All three are free and can be downloaded from the internet. ARCGIS (ESRI) is widely available on campus (the University has a site license but there is a small annual fee), SAS includes some geostatistical components (SAS is accessible through the university computer center and there is a university site license). S-Plus also has a geostatistics component (the university has a site license for this software as well).
Students may pick and choose among the software packages (in some instances using one package for a part of the analysis and another for another part). When preparing the final report for the DATA ANALYSIS PROJECT, the student should identify the software used for each set of computations.
SUGGESTED FREEWARE
This is an old reliable package, written to run under DOS but will function well in a DOS window in MS-Windows (executable codes). Although GEOEAS is a DOS program it runs in an interactive mode with windowing. GEOEAS was produced under a contract with EPA and then released into the public domain. GEOEAS uses a simple ASCII text file for both input files and output files. It is probably the easiest package to learn, in part this is because it has many "defaults" built in (the user may override any of these) Documentation is available. It has multiple components with essentially no interactivity between them (in several instances the output file of one component is an input file for another).
It is suggested that each student download and install this package even if they intend to use another.
You can capture graphs and plots generated in GEOEAS (running under a DOS with MS Windows) as follows: (1) while you have the plot on the screen, press Print Screen, (2) press q to exit the plot and return to the GEOEAS menu window, (3)go to START , Programs, Accessories, Paint, (4) Click on the Edit pull down menu and click on paste, when it asks about enlarging the screen, click yes/ok. (5) Finally use invert colors to change from a black background to a white background. You can then edit the image in various ways, save it as an image file, print, paste it into a document, i.e., using WordPerfect or Word.
VARIOWIN 2.21 is now available for free downloading at this site. Variowin is a windows based replacement for PREVAR and VARIO in GEOEAS (in particular it allows for much larger data sets. It incorporates additional interactive features. Note the requirement for including an acknowledgement in any publication wherein Variowin has been used for some part of the analyses (the book is out of print). Note that the ".pcf" file format for VARIOWIN 2.21 is not compatible with PREVAR and VARIO in GEOEAS.
There is a UNIX version of GEOEAS produced at the University of Arizona. It has now been extended in several ways, there is a Solaris version and there is a LINUX version (compiled code) see A. Long's) site for the latest information on this code
Three add-on programs were produced at the University of Arizona; CORRES (a multivariate analysis program similar to but different from Principal Components Analysis), COKRIG (a cokriging program, source code is available for this program), COKVAL (a cokriging cross-validation program, source code is available for this program).
R is essentially a free version of S-Plus. Executable codes for various operating systems are available for download at this site. R is an "object-oriented" language and functions from a command line within the window. The following two sites include tutorials (not on geostatistics) on the use of R
R and Statistics Geostatistics add-ons are found at the next four sites
The following two sites are general on the use of R.
Using R for Data Analysis and Graphics
Notes on R: A Programming Environment for Data Analysis and Graphics
Although "Spatial Statistics" is not always quite the same as Geostatistics, there are similarities and connections. The following two sites provide information on the use of R for spatial statistics
GStat is another free download geostatistical package.
GSLIB . This is actually a library of FORTRAN codes for geostatistical analysis (see the ai-geostats website for downloading information), each runs in batch mode and only in command line format. In general the user must first generate a "batch" or "parameter" file that passes parameters, file names, commands and options to the main program (this is an ASCII file and can be generated with any text editor) The user must first compile the codes (on the appropriate machine or operating system). Before compiling, the user should note the parameter limitations set in the "Include" file, these may preclude or override user choices in a batch file. GSLIB programs use the GEOEAS file formats for input and output (note that in general the output files for kriging, cokriging, simulation do not include the position coordinates, GSLIB includes a utility to add these back or relatively simple modifications of the source will preclude the necessity of using the utility). An accompanying user's manual/documentation is available for purchase.
OTHER USEFUL SITES