POV-Ray : Newsgroups : povray.advanced-users : Problems using/graphing internal sum function : Problems using/graphing internal sum function Server Time
30 Nov 2022 05:17:09 EST (-0500)
  Problems using/graphing internal sum function  
From: Bald Eagle
Date: 7 Nov 2022 19:50:00
Message: <web.6369a6d45447eee1f9dae3025979125@news.povray.org>
Something popped into my head recently, and now I am trying to write an equation
for the cumulative distribution function of a probability density function using
sum ().

I'm using a normal distribution, but when I try to graph the summation of the
values over the range of 0 through 5, I get unexpected results.

I tried using N, then since i is related to N, I tried seeing what that result
looked like, and then I averaged them...  It makes no sense that a graph of a
running tally starts to decrease, instead of being non-decreasing and
right-continuous like it should be.

#declare NDist = function (N, mu, sigma)
{1/(sigma*sqrt(tau))*exp(-0.5*pow((N-mu)/sigma,2))}


 #declare NDist_cdf = function (N, mu, sigma) {sum (i, 0, N, NDist (N, mu,
sigma))}

 #declare NDist_cdf2 = function (N, mu, sigma) {sum (i, 0, N, NDist (i, mu,
sigma))}

 #declare NDist_cdf3 = function (N, mu, sigma) {sum (i, 0, N, NDist ((i+N)/2,
mu, sigma))}

Has anyone ever tried to use sum () to graph a running tally of a function, or
have any idea what I'm doing wrong?

Have I broken POV-Ray _*AGAIN*_???!


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