MATLAB: One Plot two different y-axis, how to scale second y-axis

one data setplot two axisplotyyy axisyyaxis

How can I plot one data set with two different scales, where the second (right) y-axis has no linear relation to the left one.

I only want to see the blue dots where instead the second (right) y-axis is scaled this points.

To reverse the axis I used set(gca, 'YDir','reverse') so far though it seems with yyaxis this issue is not solvable.

How can I do this?

Best Answer

Probably not what you want, but perhaps one step closer:

x=[0 100 300 500 800 800]
y1=[0 100 180 200 255 260]
y2=[155 124 115 79 42 40]
yyaxis left
plot(x,y1,'o')
yyaxis right
plot(x,y2,'o','color','none');
set(gca,'ytick',flip(y2))
set(gca,'ylim',[min(y2) max(y2)])
set(gca, 'YDir','reverse')

Related Solutions

MATLAB: Deletting X and Y axes ticks

set(gca,'xtick',[]) set(gca,'ytick',[])

MATLAB: How to add tick just for the left axis

Here are two methods to show ticks only on the left axis.

Use yyaxis

This method creates a 2nd y axis on the right that is independently customizable and not used (unless you want to use it).

ax = axes(); 
box(ax, 'on')  % default

% Set axis tick length and direction
ax.XAxis.TickLength = [0 0];
ax.YAxis.TickDirection = 'both';
% Create 2nd y-axis on right and set y axes colors
% to match the x-axis color
yyaxis right
ax2 = gca(); 
ax.YAxis(1).Color = ax.XAxis.Color; 
ax.YAxis(2).Color = ax.XAxis.Color; 
% Remove ticks on right axis
ax.YAxis(2).TickValues = []; 
% Return control back to the left axes
yyaxis left

See image below for results.

Use xline and yline at axis limits

ax = axes(); 
box(ax, 'off')  % default
ax.XAxis.TickLength = [0 0];

If you want the y-ticks to be in both directions,

ax.YAxis.TickDirection = 'both';

If you want the right and upper axes lines but without ticks, you can make is appear as though 'box' is 'on' by setting the axis limits and adding a xline and yline.

% This syntax just sets the axis limits to their current value
xlim(ax, xlim(ax))
ylim(ax, ylim(ax))
% Set right and upper axis lines to same color as axes
xline(max(xlim(ax)), 'k-', 'Color', ax.XAxis.Color)
yline(max(ylim(ax)), 'k-', 'Color', ax.YAxis.Color)

If the axis limits change after this change, the pseudo-box lines will no longer be positioned correctly so this should happen after all other plotting and positioning is done on the axes. The first method is therefore safer.

Final result for both methods

Best Answer

Related Solutions

MATLAB: Deletting X and Y axes ticks

MATLAB: How to add tick just for the left axis

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