Graphical
plotting
functions in PAST include different types of graph, histogram, and scatter
plots. The program can also produce ternary (triangle) plots and survivorship
curves.Graphical
plotting
functions in PAST include different types of graph, histogram, and scatter
plots. The program can also produce ternary (triangle) plots and survivorship
curves.
Descriptive statistics include minimum, maximum, and mean values, population variance, sample variance, population and sample standard deviations, median, skewness, and kurtosis.
For associations or paleocommunity data, several diversity statistics can be
computed: number of taxa, number of individuals, dominance, Simpson index,
Shannon index (entropy), Menhinick's and Margalef's richness indices,
equitability, and Fisher's 
(Harper 1999).
Rarefaction (Krebs 1989) is a method for estimating the number of taxa in a small sample, when abundance data for a larger sample are given. With this method, the number of taxa in samples of different sizes can be compared. An example application of rarefaction in paleontology is given by Adrain et al. (2000).
The
program also includes standard statistical
tests for univariate data, including: tests for normality (chi-squared and
Shapiro-Wilk), the F and t tests, one-way ANOVA,
2
for comparing binned samples, Mann-Whitney's U test and Kolmogorov-Smirnov association
test (non-parametric), and both Spearman's 
and Kendall's 
non-parametric rank-order tests. Dice and Jaccard similarity indices are used
for comparing associations limited to absence/presence data. The Raup-Crick
randomization method for comparing associations (Raup
and Crick 1979) is also implemented. Finally, the program can also compute
correlation matrices and perform contingency-table analysis.
