Linear Interpolate to n equally spaced points

I have two sets of coordinate data. The rates of the two are different. I would like to linearly interpolate one tot he same length as the other. I have tried various methods of interp1 but can't seem to get what I need. An quick example would be

in_vector =[0 5 10 5 0].

Need 15 samples of this data.

out_vector = interp(in_vector, 15)

and produces and output of

[0,       1.42857, 2.85714, 4.28571, 5.71429, 7.14286, 8.57143, 10.0000, 
 8.57143, 7.14286, 5.71429, 4.28571, 2.85714, 1.42857, 0].

 Basically what interpft but linear and not FFT.

Answer 1

[dpb]

doc interp1

>> v=[0 5 10 5 0]; L=length(v);
>> interp1(1:L,v,linspace(1,L,15))
ans =
Columns 1 through 10
       0    1.4286    2.8571    4.2857    5.7143    7.1429    8.5714   10.0000    8.5714    7.1429
Columns 11 through 15
  5.7143    4.2857    2.8571    1.4286         0
>>

[kevin]

I was so close! linspace was what I was missing. Thanks!