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Got it, arms raised in triumph, LOL! Although I still couldn't pick an
integral or a polynomial out of a line-up, all I had to do was plug the
values into the formula(s) you gave me. Thank-you!
Luck,
Sebastian
--- In amibroker@xxxxxxxxxxxxxxx, "treliff" <treliff@xxx> wrote:
>
> You're welcome. Rest assured I didn't figure out the numbers myself :)
>
> Essence is that NORMSDIST is an integral that cannot be coded in AB.
> HAS is a polynomial that does a very good approximation.
>
> A while ago I submitted to TJ suggestion to include NORMSDIST and
> NORMSINV (its inverse) as native AB functions. These are essential
> functions for any statistical approach.
>
> I don't know how Tomasz would code 'm, but in any case it would speed
> up things, I assume. So far no luck.
>
> So Sebastian, or anyone using these functions, feel free to endorse
> this effort by submitting a similar request at the feedback center.
>
> http://www.amibroker.com/feedback/
>
> Thanks :)
>
> -treliff
>
> --- In amibroker@xxxxxxxxxxxxxxx, "sebastiandanconia"
> sebastiandanconia@ wrote:
> >
> >
> > A sincere thank-you for the response, I know it's a pretty arcane
> > subject. This is the nearly unintelligible math part I was talking
> > about when I said in a subsequent post that I didn't realize how
> much I
> > was asking for, LOL! I don't understand this enough to apply it to
> > what I want to do. I assume it's just a formula where I plug in the
> > values, but the "where", "how" and "why" plumb evade me.:) I'll
> work
> > on it, though.
> >
> >
> >
> > Luck
> >
> > Sebastian
> >
> >
> >
> > --- In amibroker@xxxxxxxxxxxxxxx, "treliff" <treliff@> wrote:
> > >
> > > Sebastian,
> > >
> > > The HAS function below (based on Hasting's polynomial
> approximation)
> > > gives 7-decimal accuracy of NORMSDIST.
> > >
> > > function t(x)
> > > { return 1 / (1+0.2316419*x); }
> > >
> > > function HAS(x)
> > > { return 1 - (exp(-0.5*x^2)/sqrt(2*3.141592654))*(0.31938153*t(x)-
> > > 0.356563782*t(x)^2+1.781477937*t(x)^3-1.821255978*t(x)
> > > ^4+1.330274429*t(x)^5); }
> > >
> > > -treliff
> > >
> > >
> > > --- In amibroker@xxxxxxxxxxxxxxx, "sebastiandanconia"
> > > sebastiandanconia@ wrote:
> > > >
> > > >
> > > > I came across what I consider to be a valuable stock
> market/economic
> > > > indicator, the Wright Model "B" yield-curve indicator. Using
> this
> > > > formula in Excel:
> > > >
> > > >
> > > > Probability = NORMSDIST(-2.17 - 0.76 x S + 0.35 x R)
> > > >
> > > > where "S" is the spread (10-Year Treasury yield minus 3-month T-
> Bill
> > > > yield) and "R" is the Fed Funds rate, it gives the probability
> of
> > > > economic recession within the next 4 quarters. (Only about 44%
> > > right
> > > > now, so there's some good news. I envision using this as a
> market-
> > > exit
> > > > indicator, warning when conditions are about to turn really
> ugly for
> > > > both the stock market and the economy. )
> > > >
> > > > This formula:
> > > >
> > > >
> > > > Z(x) = (1/(sqrt(2*pi()))*exp(-x^2/2))
> > > >
> > > > appears to be the actual math represented by the NORMSDIST
> > > function. I
> > > > believe AB supports all the operations in this formula.
> > > >
> > > > My problem is that I'm not math-savvy enough to make the leap
> from
> > > here
> > > > to turn this into a complete AB formula. I don't know what
> > > operation
> > > > the NORMSDIST formula performs on the Wright Model part, I don't
> > > know
> > > > what the "x" variable is supposed to be...there's no end to
> what I
> > > don't
> > > > know.:)
> > > >
> > > > Any help from my superiors in the math field (undoubtedly a VERY
> > > large
> > > > club) would be greatly appreciated.
> > > >
> > > >
> > > >
> > > > Luck to all,
> > > >
> > > > Sebastian
> > > >
> > >
> >
>
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