How do I change my Y-axis (or X-axis) values to percentage units and have these changes reflected on the axis?

For some plot, say PLOT(0:.1:1), the y-axis tick marks are specified without units at each tick mark.

I would like to change the existing ticks from 0 through 1 to 0% to 100% and have the '%' sign shown on the axis.

Answer 1

[MathWorks Support Team]

If you would like to merely add a percentage sign ('%') to your tick labels, without changing the scaling of the labels (ex. 1 ~ 1%, 100 ~ 100%), you can use built-in functions and/or properties of axis objects as of MATLAB R2015b.

If you are using MATLAB R2016b or a later release, you can use the "xtickformat", "ytickformat" and "ztickformat" functions to add '%' signs to your tick labels. Example:

>> plot(1:100)
>> ytickformat('percentage')

Please see the documentation page for "ytickformat" to view the alternative formatting options which are available:

https://www.mathworks.com/help/matlab/ref/ytickformat.html

If you are using MATLAB R2015b or R2016a, you can instead use the "TickLabelFormat" property of an axis to add a '%' sign. Example:

>> p = plot(1:100)
>> a = ancestor(p, 'axes')
>> a.YAxis.TickLabelFormat = '%g%%'

Please see the following documentation page for more information about the "TickLabelFormat" property:

https://www.mathworks.com/help/matlab/ref/matlab.graphics.axis.decorator.numericruler-properties.html#bun6izd-1-TickLabelFormat

If you would like to also change the scaling of your labels, such that 0.1 ~ 10% and 1 ~ 100%, there is currently no built-in function or property to do this. However, the units can be changed by scaling and appending the '%' sign onto the existing labels and applying the changes to the axis property "yticklabel" or "xticklabel". Example:

% Create an initial plot
  plot(0:.1:1)

% Convert y-axis values to percentage values by multiplication
   a=[cellstr(num2str(get(gca,'ytick')'*100))]; 

% Create a vector of '%' signs
   pct = char(ones(size(a,1),1)*'%'); 

% Append the '%' signs after the percentage values
   new_yticks = [char(a),pct];

% 'Reflect the changes on the plot
   set(gca,'yticklabel',new_yticks)