Hi mohamed,
I assume that
- You are using the matrix ‘metriche’ as input data for the ‘polyfitn’ function.
- The vector ‘subjective’ is used as output data for ‘polyfitn’ function.
- You want to apply ‘polyfitn’ function on each combination of 2 columns out of the 8 columns of ‘metriche’ using for loop, ‘nchoosek’ & ‘polyfitn’ functions.
Refer to the code below:
% create the required matrix from given columns
metriche = [Loudness FlucStr Roughness Sharpness Leq SIL Tonality Kurtosis]
% 'sz' stores number of columns in 'metriche'
number_of_columns = size(metriche,2)
% 'indices' stores an array of column numbers
indices = 1:number_of_columns
% 'idx' is a vector
% 'idx' stores all the column combinations when 2 columns are chosen at a
% time out of given 8 columns
idx = nchoosek(indices,2)
% use for loop to evaluate polyfit for each of the column combinations
for k = 1:size(idx,1)
% the polyfit is linear in nature (1-degree)
degree = 1
% apply polyfitn on combinations of 2 columns from 'metriche' as inputs
% 'subjective' is the output vector
% the polynomial fir is a 1-Degree fit
evaluated_polyfit = polyfitn(metriche(:,[idx(k,1) idx(k,2)]), subjective, degree)
end
For better understanding, refer to documentation of ‘nchoosek’ function in this link, and refer to the section on how combinations of elements are generated from vectors.
Hope this helps.
