Date: Dec 13, 2012 12:56 PM
Author: bartekltg
Subject: Re: How to insert a vector between two arbitrary points of a matrix?

W dniu 2012-12-13 18:28, Wojtek pisze:
> Thanks for your answer. Well, I would like the vector to fit between two
> points. It's length may be (and almost always it will be) changed to fit
> there. But how to change the size of a vector from N to M (M may be both
> bigger and smaller then N) without cropping it? Some interpolation is
> necessary. Do you have any ideas how this can be done?

new_Y = interp1(data_X, data_Y, new_X);
for linear interpolation, or

new_Y = interp1(data_X, data_Y, new_X, 'spline');
new_Y = interp1(data_X, data_Y, new_X, 'pchip');

If you want to calculate many (new_Y/X) for constant data,
use piecewise polynomial.

PP = interp1(data_X, data_Y, 'linear'/'spline'/etc, 'pp');
and ppval function.