Filled 2D plot
显示 更早的评论
I have 3 vectors, X,Y,Z in which X,Y generates one plot and X,Z generates another. However, what I want to do is plot X,Y as a 2D plot and fill the area between the curve and the X axis with colors based on the Z values. I tried using the contour plot but failed. However, then I managed to change the colour of the curve based on the Z value as follows, but I need the complete area under the curve to be filled. Is there any advice?
c= cos(Z).^2;
colormap(hsv)
patch(X,Y,Z,c,'FaceColor','none','EdgeColor','interp')
2 个评论
DGM
2021-4-16
Please provide a sufficient amount of code to constitute an example of what you're trying to do.
Ironhide Jr
2021-4-16
编辑：Ironhide Jr
2021-4-16
采纳的回答
Star Strider
2021-4-17
My apologies for the delay. I was working on other things most of today.
‘However, to make the data more concise, I am trying to plot a single figure of X vs Y in which, the area under the curve is colored based on the value of Z at that region.’
This was a bit of a challenge! However it seems to do what was requested.
The Code —
XL = load('X.mat');
YL = load('Y.mat');
ZL = load('Z.mat');
X = XL.X;
Y = YL.Y;
Z = ZL.Z;
figure
plot(X, Y)
hold on
patch([X; flipud(X)], [Y; zeros(size(Y))], [Z; flipud(Z)])
hold off
grid
cb = colorbar;
cb.Label.String = 'Z Value';
xlabel('X')
ylabel('Y')
title('Full Patch Plot')
figure
plot(X, Y)
hold on
patch([X; flipud(X)], [Y; zeros(size(Y))], [Z; flipud(Z)])
hold off
grid
cb = colorbar;
cb.Label.String = 'Z Value';
xlabel('X')
ylabel('Y')
title('Zoom Detail Patch Plot')
axis([0 20 0 5E-3])
figure
plot(X, Z)
grid
The Plots —
The ‘Z’ value is very high only in a very small part of the patch object, so the ‘zoomed’ plot is necessary to demonstrate that the code does what was requested. The maximum value of ‘Z’ occurs at an ‘X’ value of about 3.22, and that is where the colour changes the most. The ‘Z’ value is actually quite noisy, accounting for the ‘striated’ appearance of the patch colours.
8 个评论
Ironhide Jr
2021-4-17
Star Strider
2021-4-17
As always, my pleasure!
This was an interesting problem! I have a reasonable amount of experience with patch, however this was entirely new to me.
Ironhide Jr
2021-4-17
Star Strider
2021-4-17
Yes!
The patch function does not work with semilogx, so plot it with a linear scale first, then use:
set(gca, 'XScale','log')
The solution is also to add 1 to the x-vector, since log(0) is NaN and NaN values do not plot and can prevent patch from working properly.
figure
% plot(X, Y)
hold on
patch([X; flipud(X)]+1, [Y; zeros(size(Y))], [Z; flipud(Z)])
hold off
grid
cb = colorbar;
cb.Label.String = 'Z Value';
xlabel('X')
ylabel('Y')
title('Full Patch Plot')
set(gca, 'XScale','log')
.
Ironhide Jr
2021-4-17
Star Strider
2021-4-18
No wories!
As always, my pleasure!
Also, to plot logarithmic scales on both axes, this works —
figure
% plot(X, Y)
hold on
patch([X; flipud(X)]+1, [Y; zeros(size(Y))]+0.1, [Z; flipud(Z)])
hold off
grid
cb = colorbar;
cb.Label.String = 'Z Value';
xlabel('X')
ylabel('Y')
title('Full Patch Plot')
set(gca, 'XScale','log')
set(gca, 'YScale','log')
.
Ironhide Jr
2021-4-18
Star Strider
2021-4-18
As always, my pleasure!
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Surface and Mesh Plots 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
