matrix - How do I double the size of a vector in MATLAB with interpolation?

Question

Essentially, if I have the following matrix:

[1, 2, 3 ,4, 10]

I need to explode it whilst interpolating, as follows:

[1, 1.5, 2, 2.5, 3, 3.5, 4, 7, 10].

Essentially, buff it up by filling in the average of the two surrounding values.

Say if I need to do this for n instead of adding just 1 value as we have here.

Answer 1

You need to use interp1 with 'linear' interpolation method:

>> v = [1 2 3 4 10];
>> newNum = 13; % new number of elements in the "buffed" vector
>> iv = interp1( linspace(0,1,numel(v)), v, linspace(0,1,newNum) )
iv =
1.0000    1.3333    1.6667    2.0000    2.3333    2.6667    3.0000    3.3333    3.6667    4.0000    6.0000    8.0000   10.0000