Re: A point in a vector?

[Carlo de Falco]

On 30 Sep 2009, at 22:11, Corrado wrote:

> Dear list,
>
> I have a strange requirement .... I have a vector, for example
>
> v=[0,0,0,0,1,2,4,6,8,8,8,8]. I have a value,for example x=4.8.
>
> I would like to understand in which sub interval of v is x.
>
> In this case, v would be in the sub interval [4,6] that is in the  
> subinterval
> starting from element j=7 to the element j+1=8.
>
> Can we do that with an octave command?
>
> Regards
> --
> Corrado Topi


this is done as follows in the function "findspan" from the nurbs  
package

j = min (lookup (v, x, "lr") - 1, n);

just out of curiosity, is your "v" an open knot vector for a B-spline?
c.