Interpolate 3D Matrix based on frequency values

I am using m file for post processing of FEA(Finite Element Analysis) results derived from another software.

In this case I have a (a*1*c) matrix which has to be interpolated based on the third dimension 'c' . In the definition of the matrix dimension, I have assigned the dimension 'c' as just numbers starting from 1 upto the required size.

But the problem now is that the third dimension 'c' is a frequency value ( eg: 100 Hz, 300 Hz, 700 Hz, etc). I have to interpolate the (a*1) values based on the user input frequency (eg: for 250 Hz).

Again this has to be done for a number of values, which I guess can be accomplished with the help of a loop. I have the frequency values defining the dimension 'c' and the user input as a array.

Can anyone help me out with this?

Thank you very much for your time and patience.

Answer 1

[Matt J]

use the PERMUTE command to make the array dimensions c x a. Then just use interp1, e.g.,

 interp1(frequencies, Matrix_cxa, 250);

[Lokeshwaran]

Thank you very much for your answer. But can you make it clear with an example please?

[Matt J]

OK. So if you want to interpolate the matrix A below at "row 2.5", you would do

>> A=[4 5 6; 7 8 9; 10 11 12]'

A =

       4     7    10
       5     8    11
       6     9    12

>> interp1([1;2;3],A, 2.5)

ans =

      5.5000    8.5000   11.5000