GGSD Program Details for Variowin

Variowin

Category	Geostatistics
Publisher	University of Lausanne
Platform	Win3x
Status	Freeware
Description	Variowin is a collection of three Windows programs that are used for Spatial Data Analysis and Variogram Modelling in 2D. An extensive on line Help covering basic geostatistical concepts is also included. PREVAR2D builds a Pair Comparison File, i.e. a binary file containing the pairs of data sorted by increasing distance. Pair Comparison Files can be built from subsets in order to reduce memory requirements. VARIO2DP is used for Spatial Data Analysis of 2D data. It uses an ASCII data file and a binary Pair Comparison File produced by PREVAR2D. Features implemented in VARIO2DP include; Possibility to characterise the spatial continuity of one variable or the joined spatial continuity of two variables; Variogram surfaces for identifying directions of anisotropies; Directional variograms calculated along any direction; Several measures of spatial continuity. Not only the Semivariogram but also the Standardised Semivariogram, the Non Ergodic Covariance, the Non Ergodic Correlogram and the Semimadogram are used to measure spatial continuity; H-scatterplots to assess the meaning of these measures; Identification and localisation of pairs of data adversely affecting the measure of spatial continuity. Once identified, these pairs can interactively be masked from the calculation; Variogram clouds for identifying pairs of data values having the most influence on the measure of spatial continuity. Those pairs can also be located on the sample map; Possibility to save directional variograms in an ASCII file which can be used for subsequent modelling by MODEL. MODEL is used to produce a 2D general model of spatial continuity in an interactive way. Several directional variograms read from a variogram file produced by VARIO2DP are adjusted simultaneously by a 2D nested model. Adjustment is done with scroll bars and each time a parameter of the model is changed, the model is recalculated and redrawn on the directional variograms used for the fitting procedure. The 2D model can be saved in a model file which can be used for kriging or for geostatistical simulations by other public domain geostatistical packages (eg Geo-EAS, GSLIB).
Cost	Free via the WWW
Data formats supported	None stated
Supplier in Switzerland	University of Lausanne