diversity(text.var, grouping.var = NULL)
NULL generates
one word list for all text. Also takes a single grouping variable or a list
of 1 or more grouping variables.Returns a dataframe of various diversity related indices for Shannon, collision, Berger Parker and Brillouin.
Transcript apply diversity/richness indices.
These are the formulas used to calculate the indices:
Shannon index:
H_1(X)=-\sum\limits_{i=1}^R{p_i};log;p_i
Shannon, C. E. (1948). A mathematical theory of communication. Bell System
Simpson index:
D=\frac{\sum_{i=1}^R{p_i};n_i(n_i -1)}{N(N-1))}
Simpson, E. H. (1949). Measurement of diversity. Nature 163, p. 688
Collision entropy:
H_2(X)=-log\sum_{i=1}^n{p_i}^2
Renyi, A. (1961). On measures of information and entropy. Proceedings of the 4th Berkeley Symposium on Mathematics, Statistics and Probability, 1960. pp. 547-5661.
Berger Parker index:
D_{BP}=\frac{N_{max}}{N}
Berger, W. H., & Parker, F. L.(1970). Diversity of planktonic Foramenifera in deep sea sediments. Science 168, pp. 1345-1347.
Brillouin index:
H_B=\frac{ln(N!)-\sum{ln(n_1)!}}{N}
Magurran, A. E. (2004). Measuring biological diversity. Blackwell.
## <strong>Not run</strong>: # div.mod <- with(mraja1spl, diversity(dialogue, list(sex, died, fam.aff))) # colsplit2df(div.mod) # plot(div.mod, high = "red", low = "yellow") # plot(div.mod, high = "red", low = "yellow", values = TRUE) # ## <strong>End(Not run)</strong>