Re: Similar to cftool in octave?

[Marco Atzeri]

On 25.05.2020 23:53, saviobez wrote:
> Hi there
> I'm using Octave to plot the following graph
>
> <https://octave.1599824.n4.nabble.com/file/t373787/Sem_t%C3%ADtulo.png>
>
>
> Where Y = K*(X-Vt)^2
> Need to find the parameters K e Vt

It is not a parabola as it has not a vertical symmetry axis.

Your formula is symmetrical compared to Vt

The graph looks more a K*exp(X-Vt)
plot the logarithm and if you have a straight line
you have a confirmation or reject of this guess

log(Y) = log (K*exp(X-Vt)) = log(K) + X - Vt


> Is there a function similar to MatLab's cftool where I can quickly find
> these parameters? Or any idea how to find them. I tried to use the polyfit
> but I couldn't

Regards
Marco