A generic discrete random variable.
Discrete random variables are defined from a standard form.
The standard form may require some other parameters to complete
its specification. The distribution methods also take an optional location
parameter using loc= keyword. The default is loc=0. The calling form
of the methods follow:
- generic.rvs(<shape(s)>,loc=0)
-
- generic.pmf(x,<shape(s)>,loc=0)
- probability mass function
- generic.cdf(x,<shape(s)>,loc=0)
- cumulative density function
- generic.sf(x,<shape(s)>,loc=0)
- survival function (1-cdf --- sometimes more accurate)
- generic.ppf(q,<shape(s)>,loc=0)
- percent point function (inverse of cdf --- percentiles)
- generic.isf(q,<shape(s)>,loc=0)
- inverse survival function (inverse of sf)
- generic.stats(<shape(s)>,loc=0,moments='mv')
- mean('m'), variance('v'), skew('s'), and/or kurtosis('k')
- generic.entropy(<shape(s)>,loc=0)
-
- Alternatively, the object may be called (as a function) to fix
- the shape and location parameters returning a
"frozen" discrete RV object:
- myrv = generic(<shape(s)>,loc=0)
- frozen RV object with the same methods but holding the
given shape and location fixed.
You can construct an aribtrary discrete rv where P{X=xk} = pk
by passing to the rv_discrete initialization method (through the values=
keyword) a tuple of sequences (xk,pk) which describes only those values of
X (xk) that occur with nonzero probability (pk).
