Re: infinite geometric series

[Fausto Arinos Barbuto]

On 01/04/2014 05:12 PM, Fullfill wrote:
> <http://octave.1599824.n4.nabble.com/file/n4660654/1471116_731146650246828_979308716_n.jpg>
>
> Hello !
>
> I'm trying to implement infinite geometric series in octave but i don't know
> if I'm doing it correctly.
>
> function y=myfun(x)
>   an=0;
>   n=0;
>   s=1;
>   while abs(an)< 0.3
>   n=n+1;
>   an=(-3*x).^n;
>   s=s+an;
>   end%while
>   endfunction
>
> Also I don't know how to read in x-values as a vector to this function and
> get y-values as a vector.
>
> All helpful ideas great to see.
>
>
>
>
> --
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> http://octave.1599824.n4.nabble.com/infinite-geometric-series-tp4660654.html
> Sent from the Octave - General mailing list archive at Nabble.com.

Hello,

Write the function below into a file and save it as infinite.m:

%----------------------
function y=infinite(x)
    an = 0;
    n = 0;
    s = 1;
    while abs(an)< 0.3
        n = n + 1;
        an = (-3*x).^n;
        s = s + an;
    end
    y = s;
endfunction
%----------------------

Then, in a command line, try this:

x = linspace(1,5,40)
z = zeros(1,40)
z = infinite(x)

You should get something.  Hopefully, it's what you want.

Fausto