Supposing a long time ago I made a plot and now I wish to modify the plot without regenerating the data. I have the plot in a notebook and wish to get it into a new form. What options can I change? I have found a few but I need more. I guess I could get the data from the plot using this method and start afresh but this can be complex and I would rather avoid this approach. Here is a minimum working example. Let's suppose this is the old plot I made.

oldPlot = 
 Plot[Evaluate[Table[1/n Sin[2 π n t], {n, 4}]], {t, 0, 2}, 
  Frame -> True, FrameLabel -> {"Time", "Force"}, AspectRatio -> 1/3, 
  ImageSize -> 12 72, 
  PlotLegends -> 
   LineLegend[{"Force 1", "Force 2", "Force 3", "Force 4"}]]

Mathematica graphics

I now enter the following text into the notebook

newPlot =  ;

and then cut and paste the old plot (including the legend) before the ";" and press Shift-Enter. This gives me

Mathematica graphics

Now I can start playing and making changes, for example,

fig1b = Show[newPlot,
  ImageSize -> 8 72,
  AspectRatio -> 1/4,
  FrameLabel -> {"Time / s", "Force / N"},
  LabelStyle -> {FontFamily -> "Times", FontSize -> 12},
  FrameTicksStyle -> Thick]

Mathematica graphics

There are probable many more options I can change (not sure how to find them all it would be nice to know) but I can't seem to change the legend. The LabelStyle does nothing to the legend although it has nicely changed the FrameLabel. I have noticed that if I do


Mathematica graphics

I get something that seems detached from the main plot but I don't know how to change it. I also note that I can't abandon the old legend and put a new one into Show. It could be useful to do this. The main question: how do I change the legend with for example a new font and font size?


  • 1
    $\begingroup$ As a general reminder: only Graphics[] (or Graphics3D[] in the 3D case) options can be changed after the fact. So, e.g., you will not be able to change the setting of PlotPoints without regenerating your plot altogether. $\endgroup$ – J. M.'s technical difficulties Mar 14 '18 at 14:02
  • $\begingroup$ A useful observation. Fortunately in my case it is measured data so I can't make any more points. Thanks. $\endgroup$ – Hugh Mar 14 '18 at 14:04
Show[newplot /.  LineLegend[a_, b_, c___] :> 
   LineLegend[a, b, LabelStyle -> {FontFamily -> "Times", FontSize -> 12}, c], 
 ImageSize -> 8 72, AspectRatio -> 1/4, 
 FrameLabel -> {"Time / s", "Force / N"}, 
 LabelStyle -> {FontFamily -> "Times", FontSize -> 12}, 
 FrameTicksStyle -> Thick]

enter image description here

| improve this answer | |
  • $\begingroup$ Thanks for the fast response. This works nicely. Can we even adjust the vertical position of the legend since this has slipped down a bit following the new aspect ratio? $\endgroup$ – Hugh Mar 14 '18 at 12:40
  • $\begingroup$ @Hugh, maybe newplot /. Placed[LineLegend[a_, b___], _] :> Placed[LineLegend[a, b, "Spacings" -> .5, LabelStyle -> {FontFamily -> "Times", FontSize -> 12}], {After, Center}]? $\endgroup$ – kglr Mar 14 '18 at 12:57
  • $\begingroup$ I think you want LineLegend[a_, b_,c___] :> LineLegend[a, b, LabelStyle -> {FontFamily -> "Times", FontSize -> 12}] to get rid of previous options. With just LineLegend[a_, b___] the old options are retained and the new alternatives do not work. $\endgroup$ – Hugh Mar 15 '18 at 16:02
  • $\begingroup$ @Hugh good catch; thank you. $\endgroup$ – kglr Mar 15 '18 at 19:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.