Updating PlotLabels when using Manipulate for multiple plots

[gkhannacfoi (Gaurav Khanna)]

Hello – I have several examples of trying to show the change of some parameter on the shape of a function. I am plotting the “base” function (i.e., Sin[x]) and using the Manipulate function to show the changes of the function: a Sin[k x + phi]. The issue comes when I use the Manipulate function to superimpose the two functions. I would like the PlotLabel of the function being manipulated to update in real time. I’m running into the following issue:

Manipulate[
 Plot[{Sin[x], a Sin[k x + phi]}, {x, 0, 2 Pi}, 
  PlotLabels -> Placed[Automatic, Above ]],
 {k, .1, 4}, {a, 1, 2}, {phi, 0, 2 Pi}
 ]

And here is the output. As you can see, the label for the “static” function is showing up fine… but the label for the function that is being manipulated is garbled.

Any suggestions would be welcome!

[rohitnamjoshi]

Hi Gaurav,

Manipulate scopes local variables by default. To avoid that, add the option LocalizeVariables -> False.

To show the actual values of k, a, phi

Manipulate[
 Plot[{Sin[x], Evaluate[a Sin[k x + phi]]}
  , {x, 0, 2 Pi}
  , PlotLabels -> Placed["Expressions", Above]]
 , {k, .1, 4}, {a, 1, 2}, {phi, 0, 2 Pi}
 , LocalizeVariables -> False]

[gkhannacfoi (Gaurav Khanna)]

Rohit – thanks for your response and that seemed to work!

[gkhannacfoi (Gaurav Khanna)]

Rohit – I actually think what did the trick was the Evaluate function. You can see the actual expressions even if you remove the LocalizeVariables -> False condition.