Drawing outside Plot area

Question

I want to programmatically draw some objects outside the Plot area in my Plot's Epilog, like in this dummy:

I found PlotRangeClipping and hoped that would be the solution, but setting it to False only gives me a very little bit of extra space:

How can I get that extra space?

For extra credit: I want my arrows smaller and my text bigger. ArrowHeads give all kinds of sizes, but I can't seem to control it. Also, my text is positioned a bit more to the right than the arrows, but I'd like to align it left, so that I can use the same X-coordinate. Lastly, below's my code. Constructive criticism is welcome, if you're curious enough to read it :-).

dc1 = 0.1; dc2 = 0.6; period = 1; rc = 3; y0 = dc1; mint = -4; maxt = 20; 
maxt2 = maxt - (maxt - mint)/5; tsplit = 0; 
rectangleWave[t_, period_, duty_] := UnitBox[Mod[t/period, 1.]/(2. duty)];
pwm1[t_] := rectangleWave[t, period, dc1]; 
pwm2[t_] := rectangleWave[t, period, dc2]; 
pwm[t_, tsplit_] := Piecewise[{{pwm1[t], t < tsplit}, {pwm2[t], t >= tsplit}}];
step[t_, tstep_, dc1_, dc2_] := dc1 + (dc2 - dc1) UnitStep[t - tstep];

(* ripple functions *)
Clear[ripple, v1, v2, duty, t0, rc1]; 
r = Solve[{v1 + (1 - v1) (1 - E^(-duty t0/rc1)) == v2 && 
    v2 E^(-(1 - duty) t0/rc1) == v1 && ripple == v2 - v1}, {v1, v2, ripple}];
ripplemin[t0_, rc1_, duty_] = First[v1 /. r];
ripplemax[t0_, rc1_, duty_] = First[v2 /. r];
rippleampl[t0_, rc1_, duty_] = First[ripple /. r];
y0 = ripplemin[period, rc, dc1];

(* main function *)
ss = NDSolve[{rc  y'[t] + y[t] == step[t, tsplit, dc1, dc2], y[0] == dc1},
    y, {t, mint, maxt}]; 
s = NDSolve[{rc  y'[t] + y[t] == pwm[t, tsplit], y[mint] == y0}, 
    y, {t, mint, maxt}, MaxStepSize -> 0.05];

(* find end ripple *)
ripple = rippleampl[period, rc, dc2]; NumberForm[ripple, {3, 3}]
rpmin = ripplemin[period, rc, dc2];
rpmax = ripplemax[period, rc, dc2];

(* Plot *)
Plot[{pwm[t, tsplit], Evaluate[y[t] /. s], step[t, tsplit, dc1, dc2], 
    Evaluate[y[t] /. ss]}, {t, mint, maxt}, Exclusions -> None, 
    ImageSize -> {480, 300}, PlotRange -> All, PlotPoints -> 1000, 
    PlotStyle -> {Automatic, Automatic, Thick}, Axes -> {True, False}, 
    PlotRangeClipping -> False, 
    Epilog -> {{Table[{Dotted, Line[{{mint, i}, { maxt, i}}]}, {i, 0, 1, 0.2}]},
        {Dashed, Line[{{maxt2, rpmin}, {2 maxt, rpmin}}]}, 
        {Dashed, Line[{{maxt2, rpmax}, {2 maxt, rpmax}}]},
        {Text[NumberForm[ripple, {3, 3}], {maxt + 1, dc2}]},
        {Arrow[{{maxt + 0.1, rpmax + 0.1}, {maxt + 0.1, rpmax}}]},  
        {Arrow[{{maxt + 0.1, rpmin - 0.1}, {maxt + 0.1, rpmin}}]} }]

Answer 1

rcollyer gave me the right "magic word": ImagePadding does the trick. I tried

ImagePadding -> All

like he suggested, but for some reason that doesn't work. With explicit values:

ImagePadding -> {{0, 20}, {0, 0}}

it works OK. Parameters are left, right, bottom and top padding, resp.

Note that this still needs PlotRangeClipping to be False.

Thanks, rcollyer.

edit
I didn't notice it first, but with bottom padding set to 0 the bottom half of the x-axis labels is cut off:

Bug? Anyway, fixed by setting the value to 5 Simon hints to use All as parameters, which is much better than the random 5 I used. Thanks, Simon.

ImagePadding -> {{All, 20}, {All, All}}

Answer 2

Another possibility is PlotRangePadding.

Plot[{pwm[t, tsplit], Evaluate[y[t] /. s], step[t, tsplit, dc1, dc2], 
 Evaluate[y[t] /. ss]}, {t, mint, maxt}, Exclusions -> None, 
 ImageSize -> {480, 300}, PlotRange -> All, PlotPoints -> 1000, 
 PlotStyle -> {Automatic, Automatic, Thick}, Axes -> {True, False}, 
 PlotRangeClipping -> False, 

 PlotRangePadding -> {2, 0.05}, 

 Epilog -> {{Table[{Dotted, Line[{{mint, i}, {maxt, i}}]}, {i, 0, 1, 
  0.2}]}, {Dashed, 
  Line[{{maxt2, rpmin}, {2 maxt, rpmin}}]}, {Dashed, 
  Line[{{maxt2, rpmax}, {2 maxt, rpmax}}]}, {Text[
  NumberForm[ripple, {3, 3}], {maxt + 1, 
  dc2}]}, {Arrow[{{maxt + 0.1, rpmax + 0.1}, {maxt + 0.1, 
   rpmax}}]}, {Arrow[{{maxt + 0.1, rpmin - 0.1}, {maxt + 0.1, 
   rpmin}}]}}]

Answer 3

I would rather draw those Epilog things in a separate Graphics then combine them by Show:

mainplot = 
 Plot[{pwm[t, tsplit], Evaluate[y[t] /. s], step[t, tsplit, dc1, dc2],
    Evaluate[y[t] /. ss]}, {t, mint, maxt}, Exclusions -> None, 
  ImageSize -> {480, 300}, PlotRange -> All, PlotPoints -> 1000, 
  PlotStyle -> {Automatic, Automatic, Thick}, Axes -> {True, False}]

epilogplot = 
 Graphics[{{Table[{Dotted, Line[{{mint, i}, {maxt, i}}]}, {i, 0, 1, 0.2}]}, {Dashed, 
    Line[{{maxt2, rpmin}, {1.04 maxt, rpmin}}]}, {Dashed, 
    Line[{{maxt2, rpmax}, {1.04 maxt, rpmax}}]}, {Text[
     NumberForm[ripple, {3, 3}], {maxt + 1, 
      dc2}]}, {Arrow[{{maxt + 0.1, rpmax + 0.1}, {maxt + 0.1, 
       rpmax}}]}, {Arrow[{{maxt + 0.1, rpmin - 0.1}, {maxt + 0.1, 
       rpmin}}]}}]

Show[{mainplot, epilogplot}]

The PlotRange -> All setting in mainplot will ensure all contents in mainplot and epilogplot not being clipped when they are combined in Show.