Useful Tips

Statistical Distributions

ScienceSuit has a number of built-in functions for both discrete and continuous probability distributions and for each of these distributions, similar to R, ScienceSuit has four primary functions. Each function has a one letter prefix (d, p, q, r) followed by the root name of the distribution. For example, dnorm is the height of the density of a normal distribution whereas dbinom returns the probability of an outcome of a binomial distribution.

The following tables can prove to be handy to understand the meaning of the prefixes and also relating distributions to the function names. (From statistics notes of Bret Larget, 2003):

Prefix Continuous Discrete
d density probability (probability mass function)
p probability probability (cumulative distribution function)
q quantile quantile
r random random


Distribution Root
Uniform unif 
Binomial binom 
Poisson pois
Normal norm
t t
F f
Chi-square chisq
Wilcoxon Sign Rank signrank