Dear wd,
I understand you are interested in calculating the area between a plotted line and the x-axis over the interval from (x = -40) to (x = 30).
You can achieve this using MATLAB's “trapz” function, which performs numerical integration. Below is the simple code to plot the data and compute the desired area.
% Load data from Excel
data = readmatrix('example.xlsx');
%filter data
xRange = [-40, 30];
indices = (data(:,1) >= xRange(1)) & (data(:,1) <= xRange(2));
x = data(indices, 1);
y = data(indices, 2);
% Plot the data
figure;
plot(x, y, 'k');
hold on;
fill([x; flipud(x)], [y; zeros(size(y))], [0.5, 0.5, 0.5], 'FaceAlpha', 0.3, 'EdgeColor', 'none');
hold off;
xlabel('X-axis');
ylabel('Y-axis');
title('Plot of X vs Y');
% Calculate the area under the curve
areaUnderCurve = trapz(x, abs(y));
disp(['The area under the curve is: ', num2str(areaUnderCurve)]);
To learn more please go through this official MATLAB documentation of “trapz”.
Hope this helps!
Thanks
