How do you change the color of a selected area under a curve
7 views (last 30 days)
Show older comments
I want to change the color of the selected area to say black. Ultimately, I want to have several areas filled with different colors. I know Matlab has specific built-in functions for normal curves, but I want to use my own for learning. Here is some code:
function [P] = N(u,sd,L1,L2)
y1=NC(u,sd,L1);
y2=NC(u,sd,L2);
x=[u-(sd*5):.01:u+(sd*5)];
xL=(L1:.1:L2);
Px = (1/(sqrt(2*pi)*sd)).*exp((-(x-u).^2)./(2*sd.^2));
PxL = (1/(sqrt(2*pi)*sd)).*exp((-(xL-u).^2)./(2*sd.^2));
hold on;
plot(x,Px,'k','LineWidth',4);
area(xL,PxL); %**** THIS IS THE COLOR I WANT TO CHANGE *****
title('Normal Plot - P(x) vs. x');
xlabel('x'); ylabel('P(x)');
axis([u-(sd*5),u+(sd*5),0,max(Px)]);
line([L1,L1],[0,y1],'color','r','LineWidth',2);
line([L2,L2],[0,y2],'color','r','LineWidth',2);
hold off;
function [y]=NC(u, sd, L)
y=(1/(sqrt(2*pi)*sd)).*exp((-(L-u).^2)./(2*sd.^2));
Thanks
1 Comment
Jonathan Epperl
on 11 Dec 2012
What is wrong with area? See http://www.mathworks.com/help/matlab/ref/area.html and in particular the example on the very bottom.
Alternatively you could use the lower-level function patch.
Answers (1)
Babak
on 11 Dec 2012
Here it is: Note that I only changed your plot() function to fill() and I added the end point and the first point of your data to the data again. With this, the curve will be closed! and fill would fill color int he closed curve... hope it helps you and answers your question.
function [P] = N(u,sd,L1,L2)
y1=NC(u,sd,L1);
y2=NC(u,sd,L2);
x=[u-(sd*5):.01:u+(sd*5)];
xL=(L1:.1:L2);
Px = (1/(sqrt(2*pi)*sd)).*exp((-(x-u).^2)./(2*sd.^2));
PxL = (1/(sqrt(2*pi)*sd)).*exp((-(xL-u).^2)./(2*sd.^2));
hold on;
fill([x , x(end), x(1)],[Px, Px(end),Px(1)],'k'); %,'LineWidth',4);
%area(xL,PxL); %**** THIS IS THE COLOR I WANT TO CHANGE *****
title('Normal Plot - P(x) vs. x');
xlabel('x'); ylabel('P(x)');
axis([u-(sd*5),u+(sd*5),0,max(Px)]);
line([L1,L1],[0,y1],'color','r','LineWidth',2);
line([L2,L2],[0,y2],'color','r','LineWidth',2);
hold off;
function [y]=NC(u, sd, L)
y=(1/(sqrt(2*pi)*sd)).*exp((-(L-u).^2)./(2*sd.^2));
0 Comments
See Also
Categories
Find more on Graphics Performance in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!