matlabs plotyy with axis for each plot only on one side - matlab

Question

The following code shows my problem. plotyy completely fails if the ticks are not at the same positions on both sides (which is rather the normal case...)
I require a plot with two y axis but the ticks only on one side. I was suggested to use addaxis, but I do not see how that helps me, since I do not want separated axis.
clf;
clc;
xaxis = 0:0.1:25;
ydata1 = linspace(12.1712,12.7679, length(xaxis));
ydata2 = linspace(0.3597,-28.7745, length(xaxis));
[AX,H1,H2] = plotyy(xaxis, ydata1, xaxis, ydata2);
% axis limits - x axis (min to max)
xlimits(1) = min(xaxis); xlimits(2) = max(xaxis);
set(AX, 'XLim', xlimits);
set(AX(2),'XTick',[]);
% y1 axis limits
ylimits(1) = min(ydata1); ylimits(2) = max(ydata1);
ylimits(2) = ylimits(2) + (ylimits(2)-ylimits(1))*0.05;
set(AX(1), 'YLim', ylimits);
% y2 axis limits
ylimits(1) = min(ydata2); ylimits(2) = max(ydata2);
ylimits(2) = ylimits(2) + (ylimits(2)-ylimits(1))*0.05;
set(AX(2), 'YLim', ylimits);
% y1 ticks
set(AX(1),'YTick',[12.0:0.1:12.8]);
% y2 ticks
set(AX(2),'YTick',[-25:5:0]);
print(gcf, ['-r' num2str(400)], ['test' '.png' ], ['-d' 'png']);

Answer 1

to Matthias,
set the XAxisLocation to top, and disable the XTickLabel. the upper line is back now :)
set(AX(2),'XAxisLocation','top', 'XTickLabel',[])

Answer 2

Try setting the ticks to empty set:
set(AX(2),'YTick',[]);
or
set(AX(1),'YTick',[]);
Edit(1): You can manually create the labels for left side and set the right side to []:
clf;
clc;
xaxis = 0:0.1:25;
ydata1 = linspace(12.1712,12.7679, length(xaxis));
ydata2 = linspace(0.3597,-28.7745, length(xaxis));
[AX,H1,H2] = plotyy(xaxis, ydata1, xaxis, ydata2);
% axis limits - x axis (min to max)
xlimits(1) = min(xaxis); xlimits(2) = max(xaxis);
set(AX, 'XLim', xlimits);
set(AX(2),'XTick',[]);
% y1 axis limits
ylimits(1) = min(ydata1); ylimits(2) = max(ydata1);
ylimits(2) = ylimits(2) + (ylimits(2)-ylimits(1))*0.05;
set(AX(1), 'YLim', ylimits);
x = linspace(ylimits(1),ylimits(2),10);
ticks1 = arrayfun(#(t){sprintf('%2.2f',t)},x);
% y2 axis limits
ylimits(1) = min(ydata2); ylimits(2) = max(ydata2);
ylimits(2) = ylimits(2) + (ylimits(2)-ylimits(1))*0.05;
x = linspace(ylimits(1),ylimits(2),10);
ticks2 = arrayfun(#(t){sprintf('%2.2f',t)},x);
set(AX(2), 'YLim', ylimits);
ticks = cell(size(ticks1));
for i=1:numel(ticks1)
ticks{i} = sprintf('%s / %s',ticks1{i},ticks2{i});
end
% y1 ticks
set(AX(1),'YTickLabel',ticks);
% % y2 ticks
set(AX(2),'YTick',[]);

Answer 3

Here is an approach that I got from the mathworks forum. The idea is to remove the box property, which creates the tics on the opposite side.
set(AX(1),'Box','off') % Turn off box of axis 1, which removes its right-hand ticks
set(AX(2),'Box','off') % Turn off box of axis 2, which removes its left-hand ticks
The downside is, that the upper line disappears. If someone knows how to get it back that would be great. Mybe with an empty plot over the current plot with the same dimensions??

Answer 4

Here is a solution using a third axis. For this solution first turn boxes of as suggested
set(ax(1),'Box','off') % Turn off box of axis 1, which removes its right-hand ticks
set(ax(2),'Box','off') % Turn off box of axis 2, which removes its left-hand ticks
Now, additionally add a third axis at the same position.
ax3 = axes( 'Position', get(ax(1), 'Position'),...
'XAxisLocation', 'top',...
'XTickLabel', my_XTickLabels_on_top,...
'YColor', 'none',...
'YTick', [],...
'YTickLabel', [],...
'Color', 'none', ...
cell_with_further_pValPairs{:});
One can also link the 'x' axis of all axes objects. The limits and ticks will then get updated accordingly.
linkaxes([ax ax3], 'x')
This will, however, not properly update the ticks of the third axis, unless you write a proper callback, which got even more tricky to do in MATLAB 2014b and above
To make the 'real' axes the current axes, it is possible to use
axes(ax)
Example: