how to use a ready function in your code for panning and zooming on 2D plots?

Question

As I said before for the time being, I don't want to use Mathematica as a programming tool. I'm just using it as a calculater to compute integrals, solve equations, etc because of its support of symbolic math.
So my question is not about adding zooming and panning capability to your code

As you know in 3D graphics (as far as I know graphics that are created by Plot3D function) we can use:

• Click + Drag ---> Rotate
• Alt + Click + Drag ---> Zoom in and out
• Shift+Click+Drag ---> Pan

but for 2D graphics (as far as I know graphics that are created by Plot function) we don't have such capability.

I searched a bit on the net and in this site and found out that there are no built in plot manipulating interface in mathematica and I should use this code to be able to pan and zoom on 2D plots that I have created in notebook.
But I don't know how to use a certain piece of code and call a function in mathematica. I'm just starting to learn, so please pardon me if it's so trivial.

For example suppose that I have created this plot and now I want to be able to pan and zoom on it. What should I do?

Manipulate[
 Plot[PDF[VonMisesDistribution[μ, κ], x], {x, -Pi + μ, 
   Pi + μ}, PlotRange -> {{-5, 5}, {0, 20}}], {{μ, 0}, -5, 
  5}, {{κ, 5}, 0, 1000}]

Answer 1

Manipulate[
 Pane[
  Plot[Sin[x], {x, -10, 10}],
  ImageSize -> {300, 200},
  Scrollbars -> True,
  ScrollPosition -> {a, b}],
 {a, 10, 200},
 {b, 10, 200}]

Answer 2

The answer by @IstvánZachar that you linked seems to do all that you want and more:

Attributes[PlotExplorer] = {HoldFirst};
PlotExplorer[defPlot_] := 
  DynamicModule[{held, head, plot, range, zoomRange, defRange, 
    defSize, defEpilog, size, pt1, pt2, spt1, dist, rect = {}, 
    dragged = False, overButton = False, pushedButton = False, 
    overHor = False, overVer = False, activeHor = False, 
    activeVer = False, xPos = .5, yPos = .5, minDistance = 0.1, 
    sliderRatio = 0.05, panFactor = 10, reset, distance, slider, 
    replot, coord = None}, held = Hold@defPlot;
   head = Part[held, 1, 0];
   plot = defPlot;
   {defEpilog, defRange} = {Epilog, PlotRange} /. 
     Quiet@AbsoluteOptions@plot;
   defEpilog = defEpilog /. Epilog -> {};
   size = defSize = Rasterize[plot, "RasterSize"];
   range = zoomRange = defRange;
   Deploy@
    EventHandler[
     Dynamic[MouseAppearance[
       Show[plot, PlotRange -> Dynamic@range, 
        Epilog -> {defEpilog,(*Original epilog*)(*Replot button*)
          EventHandler[
           Inset[Graphics[{Black, 
              Dynamic@
               Opacity@If[overButton, If[pushedButton, .2, .1], 0], 
              Rectangle[{0, 0}, {1, 1}, RoundingRadius -> Offset@5], 
              Black, Dynamic@
               Opacity@If[overButton, If[pushedButton, .9, .7], 0], 
              Text["Replot", Center]}, ImageSize -> 50, 
             AspectRatio -> 1/2, 
             BaseStyle -> {FontFamily -> "Helvetica"}], Scaled@{1, 1},
             Scaled@{1, 1}], {"MouseEntered" :> (overButton = True), 
            "MouseExited" :> (overButton = False), 
            "MouseDown" :> (pushedButton = True), 
            "MouseUp" :> (pushedButton = False; 
              replot@plot)}],(*Zoom rectangle*)
          FaceForm@{Blue, Opacity@.1}, 
          EdgeForm@{Thin, Dotted, Opacity@.5}, 
          Dynamic@rect,(*Range sliders*)
          Inset[slider[Dynamic@xPos, Dynamic@overHor, 
            Dynamic@activeHor, size, True], Scaled@{.5, 0}, 
           Scaled@{.5, 0}], 
          Inset[slider[Dynamic@yPos, Dynamic@overVer, 
            Dynamic@activeVer, size, False], Scaled@{0, .5}, 
           Scaled@{0, .5}]}],(*cursor*)
       Which[dragged, "FrameRisingResize", CurrentValue@"AltKey", 
        Graphics[{Antialiasing -> False, Line@{{-1, 0}, {1, 0}}, 
          Line@{{0, -1}, {0, 1}}, 
          Dynamic@Text[
            Style[coord, FontFamily -> "Helvetica", 8], {0, 
             0}, {-1.1, -1}]}, ImageSize -> 160, ImagePadding -> 0, 
         AspectRatio -> 1, PlotRange -> {{-1, 1}, {-1, 1}}*8], 
        CurrentValue@"ControlKey" && ! overHor && ! overVer, 
        "ZoomView", CurrentValue@"ShiftKey" && ! overHor && ! overVer,
         "DragGraphics", 
        CurrentValue@"ShiftKey" && (overHor || overVer), "LinkHand", 
        True, Automatic]], 
      TrackedSymbols :> {dragged, 
        plot}], {"MouseMoved" :> (coord = MousePosition@"Graphics"), 
      "MouseClicked" :> 
       If[! overButton && CurrentValue@"MouseClickCount" == 2, 
        reset[]], 
      "MouseDown" :> 
       If[(! overHor || ! overVer), pt1 = MousePosition@"Graphics";
        spt1 = MousePosition@"GraphicsScaled"], 
      "MouseDragged" :> 
       If[(! overHor && ! overVer || dragged) && ! overButton && ! 
          pushedButton && ! activeVer && ! activeHor, dragged = True;
        Which[CurrentValue@"ControlKey", 
         dist = Last@MousePosition@"GraphicsScaled" - Last@spt1;
         range = 
          zoomRange*10^
            dist,(*"GraphicsScaled" is required below as "Graphics" \
would give jumpy results as the plot range is constantly modified.*)
         CurrentValue@"ShiftKey", 
         pt2 = MapThread[
            Rescale, {MousePosition@
              "GraphicsScaled", {{0, 1}, {0, 1}}, zoomRange}] - pt1;
         range = zoomRange - pt2, True, pt2 = MousePosition@"Graphics";
         rect = If[pt2 === None, {}, Rectangle[pt1, pt2]]]], 
      "MouseUp" :> (If[! CurrentValue@"ShiftKey" && ! 
           CurrentValue@"ControlKey" && dragged && 
          distance[pt1, pt2, zoomRange] > minDistance, rect = {};
         range = Transpose@Sort@{pt1, pt2};]; zoomRange = range;
        dragged = False)}, PassEventsDown -> True, 
     PassEventsUp -> True], 
   Initialization :> (slider[Dynamic[pos_], Dynamic[over_], 
       Dynamic[active_], size_, hor_] := 
      EventHandler[
       Dynamic[LocatorPane[
         If[hor, Dynamic[{pos, .5}, (pos = Clip[First@#, {0, 1}];
         range[[1]] = 
          If[CurrentValue@"ShiftKey", 

           First@zoomRange + (pos - .5)*
             Abs[Subtract @@ First@zoomRange]*panFactor, 
           First@zoomRange*10^((pos - .5)*2)]) &], 
      Dynamic[{.5, pos}, (pos = Clip[Last@#, {0, 1}];

         range[[2]] = 
          If[CurrentValue@"ShiftKey", 
           Last@zoomRange + (pos - .5)*
             Abs[Subtract @@ Last@zoomRange]*panFactor, 
           Last@zoomRange*10^((pos - .5)*2)]) &]],(*Locator below \

is required inside Graphics as LocatorPane inside Inset looses the 

crosshair image.)
         Graphics[{Black, 
           Opacity@If[(over || active) && ! dragged, .1, 0], 
           Rectangle[{0, 0}, {1, 1}, RoundingRadius -> Offset@5], 
           Opacity@1, 
           Locator[Dynamic@If[hor, {pos, .5}, {.5, pos}], 
            Appearance -> 
             If[(over || active) && ! dragged, Automatic, None]]}, 
          ImagePadding -> 0, PlotRangePadding -> 0, 
          ImageSize -> 
           If[hor, #{1, 0} + {0, 20} &, #{0, 1} + {20, 0} &]@size, 
          AspectRatio -> 
           If[hor, 1/sliderRatio/First@size, sliderRatioLast@size]], 
         Enabled -> (over || active), Appearance -> None, 
         FrameMargins -> 0, ContentPadding -> False], 
        TrackedSymbols :> {pos, over, active, 
          dragged}], {"MouseDown" :> (active = True), 
        "MouseUp" :> (active = False), 
        "MouseEntered" :> (over = ! 
            If[hor, activeVer, 
             activeHor]),(The value of active must be public so 

that one slider can check whether the other is dragged,
        not to pop up if the other locator is moved over this 

slider's area.)"MouseExited" :> (over = False)}, 
       PassEventsDown -> True];
     replot[p_] := 
      Module[{temp}, 
       Switch[head, Plot, 
        temp = ReplacePart[
          held, {{1, 2} -> {held[[1, 2, 1]], range[[1, 1]], 
             range[[1, 2]]}}];
        (Replace plot range or insert if nonexistent)
        plot = ReleaseHold@
          If[MemberQ[temp, PlotRange, Infinity], 
           temp /. {[PlotRange, _] -> (PlotRange -> range)}, 
           Insert[temp, PlotRange -> range, {1, -1}]], 
        DensityPlot | ContourPlot | RegionPlot | StreamPlot | 
         StreamDensityPlot | VectorPlot | VectorDensityPlot | 
         LineIntegralConvolutionPlot, 
        temp = ReplacePart[
          held, {{1, 2} -> {held[[1, 2, 1]], range[[1, 1]], 
             range[[1, 2]]}, {1, 3} -> {held[[1, 3, 1]], 
             range[[2, 1]], range[[2, 2]]}}];
        plot = 
         ReleaseHold@
          If[MemberQ[temp, PlotRange, Infinity], 
           temp /. {[PlotRange, _] -> (PlotRange -> range)}, 
           Insert[temp, PlotRange -> range, {1, -1}]];, , Null]];
     reset[] := (range = zoomRange = defRange; xPos = yPos = .5);
     (Quiet suppresses error message when Rescale[y,{x,
     x}] where y[NotEqual]x.EuclideanDistance then defaults to 

Infinity which is fine.)
     distance[p1, p2_, {r1_, r2_}] := 
      Quiet[N@EuclideanDistance[Rescale[p1, r1], Rescale[p2, r2]]];)];

Here is how you can run it on your plot:

dist1 /: PDF[dist1[a_, b_], x_] := Exp[b Cos[x - a]]/(2 \[Pi] BesselI[0, b])
PlotExplorer[Plot[PDF[dist1[0, 5], x], {x, -[Pi] + 0, [Pi] + 0}]]

---

How to use a certain piece of code and call a function

You don't need to learn all the intricacies of Mathematica all at once to use it, but you'll be confused and frustrated by many of the exact things that make Mathematica such an excellent tool if you don't spend a little time getting the basics down:

• making function definitions
• going further with functions
• working with variables and functions