SyntaxΒΆ

Functions are called using an R-like syntax. Some general rules:

  • Density functions: pystats.d*. For example, the Normal (Gaussian) density is called using

pystats.dnorm(<value>, <mean parameter>, <standard deviation>)

  • Cumulative distribution functions: pystats.p*. For example, the Gamma CDF is called using

pystats.pgamma(<value>, <shape parameter>, <scale parameter>)

  • Quantile functions: pystats.q*. For example, the Beta quantile is called using

pystats.qbeta(<value>, <a parameter>, <b parameter>)

  • random sampling: pystats.r*. For example, to generate a single draw from the Logistic distribution:

pystats.rlogis(<location parameter>, <scale parameter>)

The library also supports lists as input/output:

  • The pdf, cdf, and quantile functions can take list arguments. For example,

norm_pdf_vals = pystats.dnorm([x / 10 for x in range(-10, 10, 1)], 1.0, 2.0)

  • The randomization functions (r*) can output random lists of arbitrary size. For example, the following code will generate a 100-item list of iid draws from a Gamma(3,2) distribution:

gamma_rvs = pystats.rgamma(100, 3.0, 2.0)

Additionally, most parameters have defaults to most common values and named parameters are also supported. For example, to generate a single draw from a Normal(0, 2) the following can be used:

norm_draw = pystats.rnorm(sd=2.0)