inverting Z axis in plot

Hi everyone! Im a kinda' noob at matlab and I need help inverting the Z axis on a Suface plot.

The issue I have is that I need to Invert the Z axis WITHOUT inverting the 3D figure. For Example, my Z axis goes from 1 to 0 by .25 steps and the 3D figure looks all right. I need to reverse the axis, I need it from 0 to 1 without altering the 3D figure.

I Plotted a text file as DMLread.

Here is my code:

inundation = dlmread('inundation.txt','',7,0);
nx = dlmread('inundation.txt','',[0 1 0 1]);
ny = dlmread('inundation.txt','',[1 1 1 1]);

%3D map of Run-up%
figure
flip(inundation)
mesh(inundation,'FaceColor','interp')
set(gca, 'Zdir', 'reverse')
title('3D Map of Inundation')
ylabel('Mesh width')
xlabel('Mesh length')
zlabel('Height of water')

Answer 1

[Star Strider]

You only need to reverse the Z-tick labels. The plot will stay as it was.

Example —

x = linspace(-1, 1, 25);
y = linspace(-1, 1, 25);
[X,Y] = meshgrid(x,y);
Z = X.^2 .* Y.^2;

figure(1)
surf(X, Y, Z)
grid on

figure(2)
surf(X, Y, Z)
grid on
zt = get(gca, 'ZTick');
set(gca, 'ZTick',zt, 'ZTickLabel',fliplr(zt))

The plots are the same, but in figure(2). the tick labels are reversed.

[Hector Colon]

Hey Star Strider! thanks for helping me!

Although your code line works, I kind of have a little problem. If I add the lines:

zt = get(gca, 'ZTick');
set(gca, 'ZTick',zt, 'ZTickLabel',fliplr(zt))

without deactivating this one:

set(gca, 'Zdir', 'reverse')

the flip command deactivates.

so I have the situation where I need to choose the reverse command or the flipud command.

Then I tried the line:

set(gca,'YTickLabel',flipud(get(gca,'YTickLabel)))

It does invert the Axis numbers, but in the 3D figures it gives me the elevation as if the axis was in a scale from 1 to 0. I would like to read the top elevation of the 3D figure something close to 1, not 0.ish.

Any suggestions?

[Star Strider]

I don’t have your data or your plots, so it is difficult for me to determine what the problem is.

Do not use:

set(gca, 'Zdir', 'reverse')

with my code. That defeats the purpose, and will flip the Z-axis and the plot. Note that I do not use it in my code.

Also, don’t do this, because it has no effect on the Z-axis:

set(gca,'YTickLabel',flipud(get(gca,'YTickLabel')))

When I tried that, it just reversed the Y-ticks on my plot (which is symmetrical with respect to the X and Y axes, so I saw no other changes).

The lines I use in my code:

zt = get(gca, 'ZTick');
set(gca, 'ZTick',zt, 'ZTickLabel',fliplr(zt))

first get the Z-tick values, and second use those values to tell the routine where to put the Z-tick labels (the 'ZTick',zt part), and then what to put at those positions (the 'ZTickLabel',fliplr(zt) part) that flips the ‘zt’ row vector left-to-right.

If you want your plot to looks the way you described, just use my code. It will also work to flip the other axes if you want, so to flip the Y-axis, add these lines as well:

yt = get(gca, 'YTick');
set(gca, 'YTick',yt, 'YTickLabel',fliplr(yt))

The logic works the same way.