help mata fexp()
help mata Sexp()
help mata fwei()
help mata Swei()
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Title

    Simple distribution functions for use with rpnfcn()


Syntax

                Command name      Argument

                &fexp()           &theta

                &Sexp()           &theta

                &fwei()           &theta

                &Swei()           &theta


Description

    These functions compute densities and survivor function for the
    Exponential and the Weibull density, respectively. The functions are to
    be used with rpnfcn(), and use the argument vector theta to evaluate the
    function on the matrix in the current top element of the stack in
    rpnfcn(). theta must be a column vector for the Exponential distribution,
    and a matrix with two columns for the Weibull distribution.


Remarks

    The parameterizations used can be described by the following forms of the
    survivor functions

                  S_exp (x; theta1) = exp(-x * exp(theta1))

        S_wei (x; (theta1, theta2)) = exp(-(x *
        exp(theta1))^exp(theta2))

    where theta1 and theta2 are columns of theta. Note that all parameters
    are log-transformed from their natural parameterization, so as to ensure
    that they are unbounded.

Source code

    rpndist.mata

Author

    Henrik Støvring, Research Unit of General Practice, University of
    Southern Denmark.  Please email hstovring@health.sdu.dk if you have
    comments, questions or observe any problems.


Also see

    Manual:  [M] Mata Reference Manual

    Online:  help for [M-0] mata,  Evaluation of algorithm matrix using RPN,
             RPN stack manipulation functions, RPN distribution functions,
             RPN functions for integration