Only plot outline of graph
9 views (last 30 days)
Show older comments
this is my code:
% Plot the conductivity levels along the line (as an outline)
figure;
plot(lineX, conductivityValues, 'k-', 'LineWidth', 1.5, 'Marker', 'none');
xlabel('X [m]');
ylabel('Conductivity');
title(['Conductivity along Y = ', num2str(targetY)]);
box on
and now i get this plot:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1574322/image.png)
I only wantt to plot the outline of this plot how do I do this?
5 Comments
Dyuman Joshi
on 22 Dec 2023
You can plot the local maximas -
% Numerical data (generated as an example)
% Taken from Matt J's answer
N = 1e3;
t = linspace(-4, 2, N);
R = randn(1,N);
y = sin(t) + 0.5*sin(2*t) + 0.2*sin(3*t)+cos(t) + 0.5*cos(2*t) + 0.2*cos(3*t)+.2*R;
IND = (y<0);
y(IND)=abs(y(IND));
idx = islocalmax(y);
plot(t, y, t(idx), y(idx), 'k--')
Answers (2)
Matt J
on 21 Dec 2023
Edited: Matt J
on 21 Dec 2023
Use movmax to get the upper envelope of a sequence of data points, and possibly smooth it with sgolayfilt, e.g.,
% Numerical data (generated as an example)
N = 1e3;
t = linspace(-4, 2, N);
R = randn(1,N);
y = sin(t) + 0.5*sin(2*t) + 0.2*sin(3*t)+cos(t) + 0.5*cos(2*t) + 0.2*cos(3*t)+.2*R;
IND = find(y<0);
y(IND)=abs(y(IND));
yupper=sgolayfilt( movmax(y,25), 4,41);
% Data is Plotted
plot(t, y, t,yupper,'LineWidth', 1.5);
legend('Data','Outline',Location='northwest')
0 Comments
Sulaymon Eshkabilov
on 21 Dec 2023
In this exercise, envelope() with 'peaks' options does a good job, e.g.:
% Numerical data (generated as an example)
N = 1e3;
t = linspace(-4, 2, N);
R = randn(1,N);
y = sin(t) + 0.5*sin(2*t) + 0.2*sin(3*t)+cos(t) + 0.5*cos(2*t) + 0.2*cos(3*t)+.2*R;
IND = find(y<0);
y(IND)=abs(y(IND));
% Data is Plotted
plot(t, y, 'LineWidth', 1.5, 'DisplayName','Data');
hold on;
% Envelope function is applied
[UP, ~] = envelope(y,15, 'peaks');
% UPPER Envelope is plotted
plot(t, UP, 'k-', 'linewidth', 2.5, 'DisplayName','Outer Profile Shape')
legend('Location', 'Best')
hold off;
0 Comments
See Also
Categories
Find more on Line Plots in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!