MATLAB Answers

Multiple X axis in different scale, but one y axis

38 views (last 30 days)
Alpha Boy
Alpha Boy on 27 Jul 2020
Commented: Alpha Boy on 17 Aug 2020
How to Add Multiple X axis in different scale? Please help me? It will look like this:


Sign in to comment.

Accepted Answer

Adam Danz
Adam Danz on 28 Jul 2020
Edited: Adam Danz on 28 Jul 2020
Matlab does not support mutliple x axes other than the axes at the upper and lower borders of the plot.
One way to include multiple axis units is to create multi-lined x-axis ticks. The upper axis will be your main axis used to plot your data. Then define the axis limits for all additional pseudo-axes and compute the tick values for each pseudo-axis so they align with the x-ticks on the main axis. Use those value to create the multi-lined x-tick labels.
Follow the demo below and adjust it to fit your needs.
% Set up main axis (on top)
ax = axes();
ax.XTick = 0:200:2800;
ax.XLim = [0,2800];
% Set axis limits for all other axes
additionalAxisLimits = [...
0, 1400; % axis 2
19.2, 23.4; % axis 3
0.2, 3]; % axis 4
% Compute tick values for each axis to align with main axis
additionalAxisTicks = arrayfun(@(i){linspace(additionalAxisLimits(i,1), ...
additionalAxisLimits(i,2),numel(ax.XTick))}, 1:size(additionalAxisLimits,1));
% Set up multi-line ticks
allTicks = [ax.XTick; cell2mat(additionalAxisTicks')];
tickLabels = compose('%4d\\newline%4d\\newline%.1f\\newline%.1f', allTicks(:).');
% The %4d adds space to the left so the labels are centered.
% You'll need to add "%.1f\\newline" for each row of labels (change formatting as needed).
% Alternatively, you can use the flexible line below that works with any number
% of rows but uses the same formatting for all rows.
% tickLabels = compose(repmat('%.2f\\newline',1,size(allTicks,1)), allTicks(:).');
% Decrease axis height & width to make room for labels
ax.Position(3:4) = ax.Position(3:4) * .75; % Reduced to 75%
ax.Position(2) = ax.Position(2) + .2; % move up
% Add x tick labels
set(ax, 'XTickLabel', tickLabels, 'TickDir', 'out')
% Define each row of labels
ax2 = axes('Position',[sum(ax.Position([1,3]))*1.08, ax.Position(2), .02, 0.001]);
axisLabels = {'Distance (t)','Area (m^2)','Cnt from 0 (m)','KB (m)'}; % one for each x-axis
set(ax2,'XTick',0.5,'XLim',[0,1],'XTickLabel', strjoin(axisLabels,'\\newline'))
ax2.TickLength(1) = 0.2; % adjust as needed to align ticks between the two axes
Similar examples in the forum


Alpha Boy
Alpha Boy on 28 Jul 2020
Sir, Please help me. I am not requesting you to do my project. I simply want to learn. I have stuck with this for last 3 days
Adam Danz
Adam Danz on 28 Jul 2020
"in this line, what does "(1)" mean?"
Look at the value of ax.XLim. The (1) selects the first element which is the lower x-limit.
Normalization is when you convert a set of data to a different scale. A well known example is percentages. 0.2, 0.5, 0.8 can be converted to 20%, 50%, 80% by multiplying by 100. Your normalization is a bit more complicated because the data must be scaled to fit within 4000-30000.
"And where I have to write this codes, I mean which lines? at the end?"
You can normalize the data anywhere in your code after the ax.XLim is set.
I suggest doing the plotting after the axes are all set up.

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!