# [Tutor] Fitting data to error function

Colin Ross colin.ross.dal at gmail.com
Mon Mar 16 23:22:46 CET 2015

Yes, thank you, they were suppose to both be E_out.

On Mon, Mar 16, 2015 at 7:19 PM, Danny Yoo <dyoo at hashcollision.org> wrote:

> On Mon, Mar 16, 2015 at 2:55 PM, Colin Ross <colin.ross.dal at gmail.com>
> wrote:
> > What I am trying to do is calculate the non-colinear autocorrelation:
> >
> > G(t_d) = \int_{-\infty}^{+\infty} |E(t)|^2 * |E(t - t_d)|^2 dt
> >
> > So I need to loop through an array of t_d values (len = 376) and
> calculate
> > G(t_d) for as many t values as possible to eliminate sampling issues.
>
>
> Ok.  But you're using the term "E(t)" and E(t-t_d)" in your
> LaTeX-ified equation in such a way that it sounds like 'E' is context
> sensitive.
>
> Look at the Python definition of integrand() again:
>
>     100 def integrand(x,y):
> --> 101     return abs(E_out(x))**2.*abs(E_(x - y))**2.
>
>
> and note that there are *two* distinct functions here being used:
>
>     E_out
>     E_
>
> In contrast, in your mathematics, it looks like these should be the
> *same* E function, so the fact that this is *different* is worth
> consideration.  I have to assume that the mathematics has some context
> sensitivity based on the argument type that you haven't quite
> explained here.
>
>
> Also, I need to ask: do you know what is meant by the term "unit
> test"?  Because this doesn't seem to have been addressed yet, so I
> need to double check.
>