# With a ribbon plot, how to make the ribbons go along each matrix row instead of each column?

71 views (last 30 days)
Jeff Owen on 18 Jul 2024 at 17:59
Commented: dpb on 20 Jul 2024 at 22:14
In the ribbon command, the ribbons run along each column of the matrix. The Y vector must be of length = to the number of rows in the matrix. How do I get the ribbons to run along each row of the matrix? I tried many combinations of flipud, fliplr, transpose, etc., and either the axis is going in the wrong direction, or the labels are wrong.
Z=[0,1,2,2; 1,2,3,3; 2,3,4,4; 3,4,5,5]
Y=[0;1;2;3]
ribbon(Y,Z,0.1);
Here the ribbons run in the y direction, but I want them to run in the x direction. Nothing else, e.g., the axis numbering, should change.
Jeff Owen on 18 Jul 2024 at 21:14
dpb on 19 Jul 2024 at 18:15
Edited: dpb on 19 Jul 2024 at 18:16
"...With the type of figure I'm generating, I would be happy with just lines in a 3D plot"
t = 0:pi/500:pi;
X(:,1) = sin(t).*cos(10*t);
X(:,2) = sin(t).*cos(12*t);
X(:,3) = sin(t).*cos(20*t);
Y(:,1) = sin(t).*sin(10*t);
Y(:,2) = sin(t).*sin(12*t);
Y(:,3) = sin(t).*sin(20*t);
Z = cos(t);
plot3(X,Y,Z,'color','k')
Using the example of multiple lines from the doc

dpb on 19 Jul 2024 at 18:24
Edited: dpb on 19 Jul 2024 at 19:34
It can be done with plot3 excepting the Q? asked specifically how to do a ribbon.
X=[1:4];
Y=[0:3];
Z=[0,1,2,2; 1,2,3,3; 2,3,4,4; 3,4,5,5].';
plot3(X,Y,Z,'k-')
grid on
xlabel('X'), ylabel('Y')
It would be interesting to see a real dataset...
Jeff Owen on 20 Jul 2024 at 20:06
An even simpler answer. I forgot all about plot3. I was following a rabbit hole with ribbon. Nevertheless, Voss came up with a very simple way to do it. Wish I could accept both answers. You guys rock.
dpb on 20 Jul 2024 at 22:14
Indeed, his is a neat trick...but for your expressed end purpose, plot3 is probably the better tool based on your sample plots above, and not the toy dataset for the Q?

Voss on 18 Jul 2024 at 21:09
Edited: Voss on 18 Jul 2024 at 21:10
If you have some leeway on the x- and y-axis tick locations, you can use ribbon with the tranpose of Z and just alter the axis labels and orientation:
Z=[0,1,2,2; 1,2,3,3; 2,3,4,4; 3,4,5,5];
Y = (0:size(Z,2)-1).';
figure
ribbon(Y,Z.',0.1);
xlabel('y')
ylabel('x')
set(gca(),'XDir','reverse')
view([52.5,30])
dpb on 19 Jul 2024 at 14:20
Agreed that it is clever with existing ribbon function -- I started down that path but beat me here (although this response wasn't yet up). The y.' is obvious; I wasn't sure @Jeff Owen would think relabeling the axes was kosher or not...
Still, it seems a weakness in the supplied function that it doesn't have the ability to specify which axes orientation against which to draw the ribbons.
Voss on 19 Jul 2024 at 14:35
"it seems a weakness in the supplied function that it doesn't have the ability to specify which axes orientation against which to draw the ribbons"
I agree.

Voss on 18 Jul 2024 at 19:34
Z=[0,1,2,2; 1,2,3,3; 2,3,4,4; 3,4,5,5];
[m,n] = size(Z);
Y = (0:m-1).';
X = (0:n-1).';
Original ribbon plot, for reference:
figure
ribbon(Y,Z,0.1);
xlabel('x')
ylabel('y')
Create surface objects (what ribbon creates), but with the desired properties:
figure
w = 0.1;
for ii = 1:m
surface([X+1,X+1],(ii-1)*ones(n,1)+w/2*[-1 1],Z([ii ii],:).',ii*ones(n,2));
end
view(3)
grid on
xlabel('x')
ylabel('y')
Jeff Owen on 18 Jul 2024 at 21:05
Thank you so much. It absolutely meets my needs. I was going crazy trying to imagine matrix flips, rotations, and transposes in order to do it with "ribbon." You folks have come to the rescue again! :-)
Voss on 18 Jul 2024 at 21:10
Edited: Voss on 18 Jul 2024 at 21:31
You're welcome! Any questions, let me know.
Also, see my other answer, which uses ribbon and may be acceptable.

### Categories

Find more on Annotations in Help Center and File Exchange

R2023a

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!