SurveySimulator/F95/README.modelutils at d818ca2dab59bc4d50d306d8fe8dd40b9e3e768d · OSSOS/SurveySimulator · GitHub

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      subroutine psalun (i, x)

This subroutine computes a "random" number using the recurrence formala:

    i(k+1) = i(k) * 367379597 + 1 mod(2**31).

x is a double precision real "random" number between 0 (inclusive)
and 1 (exclusive). x = i/2.**31

Upon first call to psalun, one must give an initial value to i
(a seed) and then never change i (updated by the subroutine). This is a very
efficient random number generator, but with a periodicity of 2**31 only.

INPUT
    i     : Seed (I4)

OUTPUT
    i     : Seed (I4)
    x     : Random number (R8)


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      subroutine incdis (seed, nparam, param, incmin, incmax, inc,
     $  ierr, func)

This routine draws randomly a variable according to probability
density \verb|func| with parameters \verb|param|.

INPUT
    seed  : Random number generator seed (I4)
    nparam: Number of parameters (I4)
    param : Parameters (n*R8)
    incmin: Minimum value of variable (R8)
    incmax: Maximum value of variable (R8)
    func  : probability density function

OUTPUT
    inc   : Random variable (R8)
    ierr  : Error code
               0 : nominal run
              10 : wrong input data


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      subroutine incdism (seed, nparam, param, incmin, incmax, inc,
     $  dist, ierr, func)

This routine draws randomly a variable according to probability
density \verb|func| with parameters \verb|param|. Same as previous
routine, but can remember up to 10 different distributions at a time.

INPUT
    seed  : Random number generator seed (I4)
    nparam: Number of parameters (I4)
    param : Parameters (n*R8)
    incmin: Minimum value of variable (R8)
    incmax: Maximum value of variable (R8)
    dist  : index of the selected distribution (I4)
    func  : probability density function

OUTPUT
    inc   : Inclination (R8)
    ierr  : Error code
               0 : nominal run
              10 : wrong input data


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      real*8 function onecomp (nparam, param, inc)

This routine returns the unnormalized inclination "probability"
density of Brown (one component only).

INPUT
    nparam: Number of parameters (I4)
    param : Parameters (n*R8)
    inc   : Inclination (R8)

OUPUT
    onecomp: Value of the inclination (R8)


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      real*8 function onecompjmp (nparam, param, inc)

This routine returns the unnormalized inclination "probability"
density of Brown (one component only), modified to include sin(i)**2 instead of
sin(i).

INPUT
    nparam: Number of parameters (I4)
    param : Parameters (n*R8)
    inc   : Inclination (R8)

OUPUT
    onecompjmp: Value of the inclination (R8)


--------------------------------------------------------------------------------

      real*8 function size_dist_one (seed, h_params)

This function draws a number according to an exponential differential
distribution specified by "h_params":

    P(h) d_h = A \exp{(h*h_params(3))} d_h

with h_params(1) <= h <= h_params(2)

INPUT
    inc   : inclination requested (radian) (R8)

OUTPUT
    fe    : ecliptic inclination distribution (R8)