help mata runningprod()
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Title

    runningprod() -- Running product of vector


Syntax

        numeric vector     runningprod(numeric vector x [, missing])

    where optional argument missing is a real scalar that determines how
    missing values in x are treated.


Description

    runningprod(x) returns a vector of the same dimension as x containing the
    running product of x. By default, missing values turn the product to
    missing.


Remarks

    The running product of (2, 4, 6) is (2, 8, 48).

    All functions return the same type as the argument, real if argument is
    real, complex if complex.


Conformability

    runningprod(x, missing):
                x:  r x 1  or  1 x c
          missing:  1 x 1                (optional)
           result:  r x 1  or  1 x c


Diagnostics

    If missing is not specified, missing values turn the product to missing.
    Specifying missing as 1 specifies that missing values in x are to be
    treated as 1, and so on.


Author
        
        We would like to thank Nick Cox for his useful advices

        Federico Belotti
        Faculty of Economics
        Department of Financial and Quantitative Economics
        Tor Vergata University
        federico.belotti@uniroma2.it

        Silvio Daidone
        Health Policy team
        Centre for Health Economics
        The University of York

Also see

    Manual:  [M-5] runningsum()

      Help:  [M-5] sum(); [M-4] mathematical, [M-4] utility