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

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.

[dpb]

Another case along with the 3D bar() that MATLAB simply doesn't have the flexibility to change the builtin axes orientation. Why they are neutered as they are is a good question...

As both @Voss and @Star Strider show, you've got to "roll your own" for this...

[Jeff Owen]

I agree; it's an odd omission in Matlab, if indeed "ribbon" cannot be made to do the job. With the type of figure I'm generating, I would be happy with just lines in a 3D plot; no need for a ribbon surface. However, I didn't see an easy way to do that, either. "Ribbon" does the job; it's just that it seems like overkill in that one respect. Inadequate in the other respect. Thanks for the comment.

[Jeff Owen]

[dpb]

"...With the type of figure I'm generating, I would be happy with just lines in a 3D plot"

It can be done with plot3 if your Q? hadn't specifically asked about ribbon

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

Answer 1

[dpb]

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]

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]

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?

Answer 2

[Voss]

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])

[Jeff Owen]

Wow, you managed to do it with "ribbon". Your answer is very clean. It has been educational to see all these answers. Never had to use more than a simple "plot" in my whole career, so this is a big help.

[Voss]

Glad to help!

[dpb]

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]

"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.

Answer 3

[Voss]

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]

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]

You're welcome! Any questions, let me know.

Also, see my other answer, which uses ribbon and may be acceptable.