Select a point in Scope Graph

How do I select a point in the graph generated using the scope? I want to know the magnitude of the graph.

Answer 1

[Paulo Silva]

For what I can see you can't do it directly in the scope (matlab 2008b), some options:

#1 Export the signals to matlab and analyse them in there, you can save the scope data in a scope option or use the To Worspace block.

#2 Using the MinMax Running Resettable you can see the magnitude max and min of your signal, send the output of that block to one display block.

[Kai Hao Then]

I couldn't even save the graph as image file i.e. in jpeg format. Besides, I couldn't find the way to export the signals. Mind showing the way? I am using Matlab 2010a.

[Paulo Silva]

Go to the sinks library, take the To Worspace block and connect it to the place where you need to analyse the signal, now go the block To Workspace parameters (right click on it, it's one of the options), select the output format Structure with time.

Run the simulation, and plot the data like this:

plot(simout.time,simout.signals.values)

[Paulo Silva]

After plotting go to the figure toolbar and click on the Data Cursor, this will enable you to see info about the point on the line where the cursor is, click on the plot line.

[Kai Hao Then]

Thanks Paulo!

[Kai Hao Then]

I labelled the X axis and Y axis but how come when I used the data cursor to find the points, it still showed X and Y?

[Paulo Silva]

The datacursor does that by default

[Paulo Silva]

Here's another of Doug's excellent video tutorials, he must have special powers to know what tutorials do we need http://blogs.mathworks.com/videos/2011/02/25/creating-a-custom-data-cursor/

[Kai Hao Then]

Thanks!

Answer 2

[Paulo Silva]

Here's one way I just learned using the simplot function, example

vdp
set_param(gcs, 'SaveOutput', 'on')
set_param(gcs, 'SaveFormat', 'StructureWithTime')
sim(gcs)
simplot(yout)

I'm sorry for discovering this only now but it works great :)

[Kai Hao Then]

Hey no problem. Everyone learns. =)

Answer 3

[Kai Hao Then]

I have tried this command:

plot(simout.time,simout.signals.values)

It works great.

Now let's say I have 3 simout(s) i.e.

(a) simout

(b) simout1

(c) simout2

How do I type the command to show these 3 graphs?

[Paulo Silva]

%in diferent axes

subplot(311)

plot(simout.time,simout.signals.values)

subplot(312)

plot(simout1.time,simout1.signals.values)

subplot(313)

plot(simout2.time,simout2.signals.values)

%in the same axes

hold on

plot(simout.time,simout.signals.values)

plot(simout1.time,simout1.signals.values)

plot(simout2.time,simout2.signals.values)

legend('simout','simout1','simout2')

[Kai Hao Then]

Thanks!