Re: bsearch in octave

[LUK ShunTim]

On 2005-06-25 1:00, Jeff Abrahamson wrote:
> I want to find the last element in a row vector that is less than a
> given value.  I want the index of this value.  In C, for example, I'd
> use bsearch (binary search), thus the subject on my mail.
>
> I don't see how to do this in octave (besides implementing binary
> search).  Did I miss it?  Any pointers?
>
> Thanks much.
>
> For example,
>
>     bsearch([1, 3, 7, 15], 6)  ==> 2
>     bsearch([1, 3, 7, 15], 7)  ==> 3
>     bsearch([1, 3, 7, 15], 8)  ==> 3
>
> That is, 3 < 6 < 7, but 7 < 7 < 15 and 7 < 8 < 15.  And 3 has index 2,
> 7 has index 3.

This seems to be what you want.

> > a=[1,3,7,15];
> > index=find(a>6)(1) - 1
index = 2
> > index=find(a>7)(1) - 1
index = 3
> > index=find(a>8)(1) - 1
index = 3

Regards,
ST
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