How to add right ylabel with complex values (attached data and code)

I have a matrix attached called "PF". I read the matrix and plot it using pcolor. This matrix has x-label named "x_state" and left y-axis named "DR"; both attached. I want to add ylabel to the righ axis giving the complex array called "EV" attached.

Any idea?

Thanks

clear all; clc;
PF = xlsread('PF.xlsx');  % Main data to be plotted
DR = xlsread('DR.xlsx');  % used to label left y-axis
[~, TEXT, ~] = xlsread('States.xlsx'); x_state=TEXT;  % used to label x-axis
[~, TEXT, ~]  = xlsread('EV.xlsx'); EV=TEXT;  % I want to add these complex values to the right y-axis
pcolor(PF)
xticks(1:176);yticks(1:176);
xticklabels(x_state) 
xtickangle(90)
yticklabels(num2str(DR*100))  
ytickangle(0)
ylabel('DR (%)')
xlabel('States')
axis([65 96 65 96])

[Ismaeel]

Any possible help? Thanks.

Answer 1

[Alex Mcaulley]

yyaxis right

https://es.mathworks.com/help/matlab/ref/yyaxis.html

[Ismaeel]

Thanks Alex for your answer. My data for y-axis are complex values. I tried using yyaxis but I could not get any result.

[Alex Mcaulley]

Is this that you want?

clear all; clc;
PF = xlsread('PF.xlsx');  % Main data to be plotted
DR = xlsread('DR.xlsx');  % used to label left y-axis
[~, TEXT, ~] = xlsread('States.xlsx'); x_state=TEXT;  % used to label x-axis
[~, TEXT, ~]  = xlsread('EV.xlsx'); EV=TEXT;  % I want to add these complex values to the right y-axis
pcolor(PF)
xticks(1:176);yticks(1:176);
xticklabels(x_state) 
xtickangle(90)
yticklabels(num2str(DR*100))  
ytickangle(0)
ylabel('DR (%)')
yyaxis 'right'
ax = gca;
ax.YAxis(2).TickLabels = cellfun(@num2str,EV,'UniformOutput',false);
ax.YAxis(2).TickValues=1:numel(EV);
ylabel('EV (%)')
xlabel('States')
axis([65 96 65 96])

[Ismaeel]

Thanks Alex for your efforts. Yes, but when I zoom in or out, the right y-axis labels do not change accordingly; they are consant unlike the left y-axis labels. Is there a way to solve this? Thanks once again.

Answer 2

[Star Strider]

Try this:

x1 = sort(rand(1,10));                                                  % Create Data
y1 = rand(1,10);                                                        % Create Data
x2 = sort(rand(1, 15));                                                 % Create Data
y2 = rand(1, 15)+0.5;                                                   % Create Data

figure
ax = gca;
yyaxis left
plot(x1, y1)
yyaxis right
plot(x2, y2)
yt2 = ax.YAxis(2).TickValues;                                           % Get Current Yick Values
ytv = sort(exp(1j*rand(1,7)));                                          % Define Complex YAxis(2) Tick Values
yt2new = linspace(min(yt2), max(yt2), numel(ytv));                      % Create Tick Positions Corresponding To ‘ytv’
y2lbls = sprintfc('%.3f%+.3fj', ytv);                                   % Create Complex YAxis(2) Tick Labels Cell Array: ‘sprintfc’
y2lbls = compose('%.3f%+.3fj', ytv);                                    % Create Complex YAxis(2) Tick Labels Cell Array: ‘compose’
ax.YAxis(2).TickValues = yt2new;                                        % Set New Tick Values
ax.YAxis(2).TickLabels = y2lbls;                                        % Set New Tick Labels

You already have a vector for ‘ytv’, so substitute it for my vector. (Keeping the names the same with a different vector will simplify your using my code.)

Experiment to get the result you want.

[Ismaeel]

Thanks Star Strider. The problem is that the labels of one axis is fixed and the other change. In your example, left y-axis is constat regardless zooming in or out. In my example using your code, the right y-axis is constant. In my work, both should change at the same time with the scale.

[Star Strider]

My pleasure.

With fixed ‘YAxis(2).TickValues’ designations, the ticks and tick values will remain fixed, since defining them as you do here over-rides any interpolation the plot functions would otherwise do. They will scale correctly when you expand the axes by zooming in on the plot, however they will not interpolate.

I also replaced your pcolor call with an imagesc call.

Try this:

PF = xlsread('PF.xlsx');  % Main data to be plotted
DR = xlsread('DR.xlsx');  % used to label left y-axis
[~, TEXTx, ~] = xlsread('States.xlsx'); 
x_state=TEXTx;  % used to label x-axis
[~, TEXTy2, ~]  = xlsread('EV.xlsx'); 
EV=TEXTy2;  % I want to add these complex values to the right y-axis

figure
imagesc(PF)
ax = gca;
yyaxis left
ax.XAxis.TickValues = (1:176);
ax.YAxis(1).TickValues = (1:176);
ax.YAxis(1).FontSize = 6;
xticklabels(x_state) 
xtickangle(90)
ax.XAxis.FontSize = 6;
yyaxis right
yt2 = ax.YAxis(2).TickValues;                                           % Get Current Yick Values
yt2new = linspace(min(yt2), max(yt2), numel(EV));                       % Create Tick Positions Corresponding To ‘ytv’
ax.YAxis(2).TickValues = yt2new;                                        % Set New Tick Values
ax.YAxis(2).TickLabels = EV;                                            % Set New Tick Labels
ax.YAxis(2).FontSize = 6;

Experiment to get the result you want.

[Ismaeel]

I tried your last code, but still same result as shown in the figure attached. Please see how the left y-axis change when I zoomed it in, whereas the right y-axis stayed unchanged.

[Star Strider]

The right y-axis is defined not only by your fixing the tick positions and values, but also by defining them as a cell array of text values.

The left y-axis is defined as a continuous vector of integer values, however note that the left y-axis remains fixed with integer values. They will not change either (for example to decimal fractions) if you zoom them.

[Ismaeel]

Thanks Star Stider. I gave it another try but with no progress.

[Star Strider]

My pleasure.

Answer 3

[Ismaeel]

Plotting is a basic problem in many fileds. I wonder how Matlab after years of feedbacks did not solve such a problem. The prolem is simple, one wants to plot data with additional right y-axis given by complex values. There should be no hard coding to plot such data.