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WinGslib Help Page: Postscript Programs

These programs create the most commonly needed geostatistical graphics in PostScript format. They are used for data analysis prior to any modeling and to evaluate the results of modeling.

Histograms (histplt) to view a histogram and summary statistics of data with or without weights to account for declustering of volumetric support. A reference value and box plot may displayed in place of the variable name on the horizontal axis.

Probability Paper (probplt) the traditional probability paper plots are useful to display the data free of the arbitrary classes used in histograms. The plot is a cross plot of the cumulative probability of each data plotted against the data value. The probability axis is such that the points will fall on a straight line if the data follow a normal distribution. A lognormal distribution is revealed by a straight line when a logarithmic scale is used for the variable axis.

Scattergram (scatplt) the scattergram or scatterplot displays paired samples on arithmetic, semilog, or logarithmic scales. A third variable may be used to gray-scale code the samples (for rock types or another continuous third variable). The declustering weights are used for calculating the statistics and correlation coefficients.

Q-Q Plots (qpplt) this program will generate a Q-Q or P-P plot. The Q-Q plot is used extensively whereas the P-P plot is rarely used. A Q-Q plot is a useful tool to compare two different data distributions. It is not really intended for paired samples, rather the idea is to compare two different data distributions (two different measurement techniques, original data distribution and simulated values, and so on).

Location Map (locmap) an X/Y (or any two variables) plot for scattered sample values indicated by gray- or color- scale coded circles. The data values may also be labeled. The axis have the same PostScript distance units as the 2-D map (pixelplt) so the experienced PostScript user can directly edit the points into the pixelplt for data checking.

2-D Map (pixelplt) an orthogonal slice through a regular gridded data set. The values are gray- or color-scale coded. Most common application is to display a kriged or simulated model on a series of slices. Although 3-D visualization is needed for more complete validation, these 2-D views are useful.

Bivariate Probability Density Map (bivplt) A very particular program to plot the combined results of the histsmth and scatsmth programs. Note that this program is not commonly used in practice.

Variogram Plot (vargplt) plots experimentally calculated variogram points (result of gam or gamv) and/or variogram model (result of vmodel). Any number of variograms can be plotted as a series of points and/or lines.


The PostScript graphics may be printed directly to a PostScript printer or loaded in the gsview/ghostscript program (see links for where to download free of charge). The PostScript output must be converted to an EPS file prior to loading into the Microsoft Office programs or similar software. Some graphics programs like Corel Draw or Adobe Illustrator can be used, but a two-step procedure in gsview works well:

The result can be loaded into Office, but you will not see the high resolution image until you print to a PostScript printer. ---