issue when creating a long vector

I'm trying to interpolate a huge vector, and I got a problem. Here it is:

numel(unique(diff(1:2e-5:30))) is not equal to 1 ! That means that when I ask matlab to create a vector, it does not always have the same difference between each value.

It's pretty anoying, since in ordre to make the interp1 works, apparently I need that!

It could be related to the double, but I double that.

In any case, this is pretty annoying. What should I do?

(ps: using matlab 2012b)

Answer 1

[Azzi Abdelmalek]

like you mentioned it, it has to do with the ways that floating numbers are stored in memory. You can't do anything about that. Read http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F

Answer 2

[Jos (10584)]

You can scale the values before you use interp1. Something along these lines:

xi = 1:60e5;
x_scaled = x * 1e5 ;
yi = interp1(x_scaled, y , xi)