Why do tick directions change when log scaling x-axis?

I just updated to Matlab 2018b (9.5.0.94444444) and I have come across a weird glitch when changing a plot axis scaling to logarithmic, from linear. I haven't come across this problem before in previous versions, but I haven't found a solution to this maddeningly simple problem. Here's an example that highlights the issue I see:

figure(1)
ha1 = subplot(2,1,1);
plot(1:10,linspace(1,100,10))
ha1.XDir = 'reverse';
title(ha1,'Linear axis scaling: no problem')
ha2 = subplot(2,1,2);
plot(1:10,linspace(1,100,10))
ha2.XDir = 'reverse';
ha2.XScale = 'log';
title(ha2,'X-axis log-scaled: tick direction problem')

Now with ha2, the x- and y-axes behave contrastly when setting:

ha2.TickDir = 'in';% or 'out'

Changing TickDirMode to "manual" or "auto" has no affect.

Any help is appreciated. Thanks.

[Dave Ortiz-Suslow]

I wouldn't say the question is "answered", but the solution seems to be to download 2019a.

Answer 1

[Shawn Duenas]

Try this:

ha1.XDir = 'normal';
set(ha1,'view',[-180,-90])

I get that same issue:

Changing ytick direction is backwards. Check out the effect of this:

yax=get(gca,'yaxis');
set(yax,'tickdirection','in')
set(yax,'tickdirection','out')

I think it's because the plotting algorithm when xdir is reversed is stupid.

[Dave Ortiz-Suslow]

Changing the view is a quick and easy fix, but may not be general for all cases. Anyway, thanks for the contribution, the best solution will probably be to update versions.

FYI, the solution is fiddling with the view angle on a simple line plot to effectively reverse the axis direction.

Answer 2

[Cris LaPierre]

I wonder if it is related to this question. There, it was a bug potentially related to having an exponent in the axis.

[Walter Roberson]

If it was... I wonder if setting the Exponent or ExponentMode properties could help? (I note from what you linked to that HG2 is involved.)

[Dave Ortiz-Suslow]

Cris: Thanks a lot for the response. It might be a related problem, but I arrive at it when applying a logarithmic scaling to the x-axis (rather than having an exponent applied to the ticks). The answer to that question is not very general and also, it's kind of a clunky solution to a problem that shouldn't even be an issue--at least it never was in any previous Matlab version.

Walter: I haven't had to mess with that before, but I'll see if it helps.

Thanks for the responses, I'll see if the suggestions pan out.

[Cris LaPierre]

But the root cause is the same - reversing the direction of one of the axes. Don't do that, and your labels will appear normal.

Agreed - it shouldn't be there. But that's the nature of bugs. They are not there intentionally.

FWIW, I checked this in the 2019a prerelease software (might be able to see it here if you have access). This bug has been fixed.

[Dave Ortiz-Suslow]

Cris: Thanks for checking it in 2019a, I'll see about getting the prerelease.

Answer 3

[Dave Ortiz-Suslow]

A 50% answer to this question is to force the glitch on both the x- and y-axes. See code and figure below. The solution to the missplaced tick labels must be addressed following this question, which is not very satisfying. From Cris, maybe the best solution is to update to 2019 version.

figure(1)
ha1 = subplot(3,1,1);
plot(1:10,linspace(1,100,10))
ha1.XDir = 'reverse';
title(ha1,'Linear axis scaling: no problem')
ha2 = subplot(3,1,2);
plot(1:10,linspace(1,100,10))
ha2.XDir = 'reverse';
ha2.XScale = 'log';
title(ha2,'X-axis log-scaled: tick direction problem')
ha2.TickDir = 'in';% or 'out'
ha3 = subplot(3,1,3);
plot(1:10,linspace(1,100,10))
ha3.XScale = 'log';
ha3.XDir='reverse';ha3.YDir='reverse'
title(ha3,'X-axis log-scaled: tick direction wrong on both sides')
ha3.TickDir = 'out';