Averaging matrix values after Interpolation

Hey, I have a matrix that is 1x24. Within each cell is another matrix that is a single column. However, the column length changes from one matrix to another. Is there a way to average the first row from each matrix, and output into a new matrix where the first cell is the average of all the matrix first cells? Then second and third all the way to the end?

Here is my script so far. You can see that I create a matrix. Now I would like to average them (after I interpolate them).

close all
clear
clc

k = cell(1,2);
for k=1:24
   data{k} = xlsread('C:\data.xlsx',['PKA', num2str(k)]);
end

for i=1:24
xfinal{i}=data{1,i}(end,1);
xi{i}=0:0.001:xfinal{i};
xi{i}=transpose(xi{i});

x{i}=data{1,i}(:,1);
y{i}=data{1,i}(:,4);

yi{i} = interp1(x{i},y{i},xi{i});

end

[Jan]

You mean:

data = cell(1,24);  % Not k = cell(1,2)

"k" is overwritten in the next line by the counter of the for loop.

You mix the terms "cell" and "matrix" randomly. Better use "cell matrix" and "cell element" if you talk about cell objects only.

Answer 1

[Jan]

Which is the cell you want to average over? If it is yi:

v = zeros(1,24);
for k = 1:24
  v(k) = yi{k}(1);
end
meanV = mean(v);

Now it matters what "Then second and third all the way to the end" exactly means, because the vectors have a different size. What is "end" then?

What about joining the vectors to a matrix and padding it with NaNs:

Len    = cellfun('length', yi);
V      = NaN(max(Len), 24);
for iC = 1:24
  V(1:Len(iC), iC) = yi{iC};
end

Now you can uses nanmean or mean(V, 1, 'omitnan') to calculate the average.