Calculate all slopes of arrays in a cell

Hello,

I generated a cell structure with 6 2100*4 arrays.

I want to calculate the slope of the first(x) and the second column (y) of each array in the cell.

Is there any way to operate individual element in a cell and return the list of outputs?

Thank you?

[Anni Shi]

Here is my code, but I can only get one value instead of 6 slope values:

for i=1:10
      a=Allmsd{i};
      for j = 1: length(a)
        t = a(301:500,1);
        x = a(301:500,2);
        P= polyfit(t,x,1);
        slope = P(1);
        end
      Allmsd(i)=slopes
 end

[David Hill]

Attach your data if you can.

[Anni Shi]

Data file is attached. Thank you for the reminder!

Answer 1

[Image Analyst]

Try this:

% Demo by Image Analyst
% Initialization Steps.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 18;
s = load('test_data.mat')
Allmsd = s.Allmsd
[rows, columns] = size(Allmsd)
slopes = zeros(rows, 1);
subplot(2, 1, 1);
for k=1:numel(Allmsd)
    thisArray = Allmsd{k};
    x = thisArray(:, 1);
    y = thisArray(:, 2);
    % Get rid of nans.
    badIndexes = isnan(x) | isnan(y);
    x(badIndexes) = [];
    y(badIndexes) = [];
    plot(x, y, '-', 'LineWidth', 2);
    grid on;
    hold on;
    coefficients = polyfit(x, y, 1)
    slopes(k) = coefficients(1)
end
legend
title('Individual Curves', 'FontSize', fontSize)
% Plot slopes
subplot(2, 1, 2);
bar(slopes)
grid on;
title('Slopes', 'FontSize', fontSize)