Is it possible to change the values of the variables in Manipulate? Suppose I have a Manipulate with two variables, x and y and we display the values. What I want to do is to make it in such a way that when I change the value of x, y gets updated to x*x. When I change the value of y, then x gets updated to the square root of y.
The other question is, can I have multiple panels in Manipulate? I would like to have a white panel under each slider.
Manipulate[
Row[{x, y}, " "],
Row[{
Control[{{x, 0, Style["x", "TI", 14]}, 0, 4 , Appearance -> "Labeled"}],
Control[{{y, 0, Style["y", "TI", 14]}, 0, 16, Appearance -> "Labeled"}]
}]
]
In the above plot I have set x to 3 and y to 9. Again, I would like to move y to say 4 and have x to move to 2. Similarly, I want to move x to 4 and have y move to 16.
Is is possible? or have I just encountered the chicken or the egg problem?
A bit hack-ish but to couple the sliders and get two panels, you could also do something like this
Panel[DynamicModule[{x, y, width = 250},
Grid[{{
Labeled[Slider[Dynamic[x, (x = #; y = #^2) &], {0, 5}],
{Style["x", "TI", 14], Dynamic[x]}, {Left, Right}],
Labeled[Slider[Dynamic[y, (y = #; x = Sqrt[#]) &], {0, 25}],
{Style["y", "TI", 14], Dynamic[y]}, {Left, Right}]},
Framed[Pane[#, width, Alignment -> Center], FrameMargins -> 10,
Background -> White, FrameStyle -> {Gray}] & /#
{Row[{"x=", Dynamic[x]}], Row[{"y=", Dynamic[y]}]}}, Alignment -> Left]]]
Screenshot:
How about
DynamicModule[{x = 0},
{Slider[Dynamic[x], {0, 1}],
Slider[Dynamic[x^2, (x = Sqrt##) &], {0, 1}]}]
which is a trivial modification of a code snippet I found in tutorial/IntroductionToDynamic in the docs?
EDIT: You can add panels etc as follows:
DynamicModule[{x = 0},
Row[{Column[{Slider[Dynamic[x], {0, 1}], Panel#Dynamic#x}],
Column[{Slider[Dynamic[x^2, (x = Sqrt##) &], {0, 1}],
Panel#Dynamic#Sqrt[x]}]}]]
It might be better to have each question separate. Hard to answer 2 questions in same place.
For the first question, you can use your own Dynamics to obtain better control. Here is one way:
Manipulate[
Row[{
Dynamic[Refresh[Text#Row[{"x=",x," y=",y}],TrackedSymbols->{event}]],
Dynamic[Refresh[event=Date[];y=x*x;"",TrackedSymbols->{x}]],
Dynamic[Refresh[event=Date[];x=Sqrt[y];"",TrackedSymbols->{y}]]
}],
{{x,2,"x"},0,100,1},
{{y,2,"y"},0,1000,1},
{{event,0},ControlType->None},
TrackedSymbols:>{None}
]
For your second question, a Manipulate, has one 'panel' where output goes to. So, you can't really do it with one Manipulate. But you can nest Manipulates, so you can do it that way by having each manipulate with its own controls all under one Manipulate.
Update1:
To share variables between 2 inner Manipulate, so when one Manipulate update its own variable, the other Manipulate sees the latest update, here is one possible way. When you movbe one Manipulate slider, the second Manipulate updates automatically with the new value.
Manipulate[
Grid[{{
Manipulate[( gx=x; Row[{"x=",x," y=",gy}]),
{{x,1,"x="},0,10,1}],
Manipulate[( gy=y; Row[{"x=",gx," y=",y}]),
{{y,1,"y="},0,10,1}]
}}],
{{gx,0},ControlType->None},
{{gy,0},ControlType->None},
ControlPlacement->Bottom
]
Related
First of all I would like to apologize for the newbie question.
I am just starting up with mathematica and I have 2 simple plots. What i want to do is have Mathematica automatically find the intersections, label them and show me the coordinates.
I have searched this forum and there are a lot of similar questions, but they are too advanced for me.
Can someone explain how i can do this the easiest way?
Solve for equality. Get values for the points using replacement : points = {x, x^2} /. sol would work just as well. Offset the labels and set as text in epilog.
sol = Solve[x^2 == x + 2, x];
points = {x, x + 2} /. sol;
offset = Map[# + {0, 3} &, points];
Plot[{x^2, x + 2}, {x, -6, 6},
Epilog -> {Thread[Text[points, offset]],
Blue, PointSize[0.02], Point[points]}]
I need help. I have many variables, that I use in my Graphics[] command, that are dependent of one variable (H in my example). I want to manipulate my graphic so that by changing value of H graphic changes accordingly. But it is not as easy as I've thought.
If you have any idea on how to acomplish this, I would be grateful.
(*This variables are dependent on H that I want to change in
manipulate*)
R = 10;
\[Alpha] = ArcSin[H/R];
p = H/Tan[\[Alpha]];
n = 1.5;
\[Beta] = ArcSin[n Sin[\[Alpha]]];
\[Theta] = \[Beta] - \[Alpha];
l = H/Tan[\[Theta]];
(*This is the graphic I want to make manipulated*)
Graphics[{(*Incident ray*)Line[{{-2, H}, {p, H}}],(*Prism*)
Circle[{0, 0}, R, {0, Pi/2}],
Line[{{0, 0}, {0, 10}}],(*Refracted ray*)
Line[{{p, H}, {p + l, 0}}],(*Surface*)
Line[{{0, 0}, {p + l + 10, 0}}]}]
Here's one of my solutions but it's really messy. What I did is just manually pluged in those values. Is there any more appropriate way to acomplish this:
R = 10;
n = 1.5;
Manipulate[
Graphics[{(*Incident ray*)
Line[{{-2, H}, {H/Tan[ArcSin[H/10]], H}}],(*Prism*)
Circle[{0, 0}, R, {0, Pi/2}],
Line[{{0, 0}, {0, 10}}],(*Refracted ray*)
Line[{{H/Tan[ArcSin[H/10]],
H}, {H/Tan[ArcSin[H/10]] +
H/Tan[ArcSin[n Sin[ArcSin[H/10]]] - ArcSin[H/10]],
0}}],(*Surface*)
Line[{{0,
0}, {H/Tan[ArcSin[H/10]] +
H/Tan[ArcSin[n Sin[ArcSin[H/10]]] - ArcSin[H/10]] + 10,
0}}]}], {H, 0.0001, 10, Appearance -> "Labeled"}]
And also how to make my graphic not to change it's size constantly. I want prism to have fixed size and incident ray to change its position (as it happens when H gets > 6.66 in my example above / this solution).
The question is maybe confusing, but if you try it in Mathematica, you'll see what I want. Thank you for any suggestions.
I think your solution is not bad in general, Mark already noticed in his reply. I loved simplicity of Mark's solution too. Just for the sake of experiment I share my ideas too.
1) It is always a good thing to localize your variables for a specific Manipulate, so their values do not leak and interfere with other dynamic content. It matters if you have additional computation in your notebook - they may start resetting each other.
2) In this particular case if you try to get read of extra variables plugging expressions one into each other your equations became complicated and it is hard to see why they would fail some times. A bit of algebra with help of functions TrigExpand and FullSimplify may help to clarify that your variable H has limitations depending on refraction index value n (see below).
3) If we are aware of point (2) we can make variable n dynamic too and link the value H to n (resetting upper bound of H) right in the controls definition, so always it should be H<10/n . If[..] is also necessary so the controls will not “pink”.
4) If your formulas would depend on R we could also make R dynamic. But I do not have this information, so I localized R via concept of a “dummy“ control (ControlType -> None) – which is quite useful concept for Manipulate.
5) Use PlotRange and ImageSize to stop jiggling of graphics
6) Make it beautiful ;-)
These points would be important if you’d like, for example, to submit a Demonstration to the Wolfram Demonstration Project. If you are just playing around – I think yours and Mark’s solutions are very good.
Thanks,
Vitaliy
Manipulate[If[H >= 10/n, H = 10/n - .0001]; Graphics[{
{Red, Thick, Line[{{-2, H}, {Sqrt[100 - H^2], H}}]},
{Blue, Opacity[.5], Disk[{0, 0}, R, {0, Pi/2}]},
{Red, Thick, Line[{{Sqrt[100 - H^2], H},
{(100 n)/(Sqrt[100 - H^2] n - Sqrt[100 - H^2 n^2]), 0}}]}},
Axes -> True, PlotRange -> {{0, 30}, {0, 10}},
ImageSize -> {600, 200}], {{R, 10}, ControlType -> None},
{{n, 1.5, "Refraction"}, 1.001, 2, Appearance -> "Labeled"},
{{H, 3, "Length"}, 0.0001, 10/n - .0001, Appearance -> "Labeled"}]
I think your first batch of code looks fine and is easy to place into a Manipulate. I would recommend use of the PlotRange option in Graphics.
R = 10;
n = 1.5;
Manipulate[
\[Alpha] = ArcSin[H/R];
p = H/Tan[\[Alpha]];
\[Beta] = ArcSin[n Sin[\[Alpha]]];
\[Theta] = \[Beta] - \[Alpha];
l = H/Tan[\[Theta]];
Graphics[{
Line[{{-2, H}, {p, H}}],(*Prism*)
Circle[{0, 0}, R, {0, Pi/2}],
Line[{{0, 0}, {0, 10}}],(*Refracted ray*)
Line[{{p, H}, {p + l, 0}}],(*Surface*)
Line[{{0, 0}, {p + l + 10, 0}}]},
PlotRange -> {{-1,33},{-1,11}}],
{H,0.0001,6,Appearance->"Labeled"}]
Frequently I have to visualize multiple datasets simultaneously, usually in ListPlot or its Log-companions. Since the number of datasets is usually larger than the number of easily distinguishable line styles and creating large plot legends is still somewhat unintuitiv I am still searching for a good way to annotate the different lines/sets in my plots. Tooltip is nice when working on screen, but they don't help if I need to pritn the plot.
Recently, I played around with the Mesh option to enumerate my datasets and found some weird stuff
GraphicsGrid[Partition[Table[ListPlot[
Transpose#
Table[{Sin[x], Cos[x], Tan[x], Cot[x]}, {x, 0.01, 10, 0.1}],
PlotMarkers -> {"1", "2", "3", "4"}, Mesh -> i, Joined -> True,
PlotLabel -> "Mesh\[Rule]" <> ToString[i], ImageSize -> 180], {i,
1, 30}], 4]]
The result looks like this on my machine (Windows 7 x64, Mathematica 8.0.1):
Funnily, for Mesh->2, 8 , and 10 the result looks like I expected it, the rest does not. Either I don't understand the Mesh option, or it doesn't understand me.
Here are my questions:
is Mesh in ListPLot bugged or do I use it wrongly?
how could I x-shift the mesh points of successive sets to avoid overprinting?
do you have any other suggestions how to annotate/enumerate multiple datasets in a plot?
You could try something along these lines. Make each line into a button which, when clicked, identifies itself.
plot=Plot[{Sin[x],Cos[x]},{x,0,2*Pi}];
sinline=plot[[1,1,3,2]];
cosline=plot[[1,1,4,2]];
message="";
altplot=Append[plot,PlotLabel->Dynamic[message]];
altplot[[1,1,3,2]]=Button[sinline,message="Clicked on the Sin line"];
altplot[[1,1,4,2]]=Button[cosline,message="Clicked on the Cos line"];
altplot
If you add an EventHandler you can get the location where you clicked and add an Inset with the relevant positioned label to the plot. Wrap the plot in a Dynamic so it updates itself after each button click. It works fine.
In response to comments, here is a fuller version:
plot = Plot[{Sin[x], Cos[x]}, {x, 0, 2*Pi}];
sinline = plot[[1, 1, 3, 2]];
cosline = plot[[1, 1, 4, 2]];
AddLabel[label_] := (AppendTo[plot[[1]],
Inset[Framed[label, Background -> White], pt]];
(* Remove buttons for final plot *)
plainplot = plot;
plainplot[[1, 1, 3, 2]] = plainplot[[1, 1, 3, 2, 1]];
plainplot[[1, 1, 4, 2]] = plainplot[[1, 1, 4, 2, 1]]);
plot[[1, 1, 3, 2]] = Button[sinline, AddLabel["Sin"]];
plot[[1, 1, 4, 2]] = Button[cosline, AddLabel["Cos"]];
Dynamic[EventHandler[plot,
"MouseDown" :> (pt = MousePosition["Graphics"])]]
To add a label click on the line. The final annotated chart, set to 'plainplot', is printable and copyable, and contains no dynamic elements.
[Later in the day] Another version, this time generic, and based on the initial chart. (With parts of Mark McClure's solution used.) For different plots 'ff' and 'spec' can be edited as desired.
ff = {Sin, Cos, Tan, Cot};
spec = Range[0.1, 10, 0.1];
(* Plot functions separately to obtain line counts *)
plots = Array[ListLinePlot[ff[[#]] /# spec] &, Length#ff];
plots = DeleteCases[plots, Line[_?(Length[#] < 3 &)], Infinity];
numlines = Array[Length#Cases[plots[[#]], Line[_], Infinity] &,
Length#ff];
(* Plot functions together for annotation plot *)
plot = ListLinePlot[##spec & /# ff];
plot = DeleteCases[plot, Line[_?(Length[#] < 3 &)], Infinity];
lbl = Flatten#Array[ConstantArray[ToString#ff[[#]],
numlines[[#]]] &, Length#ff];
(* Line positions to substitute with buttons *)
linepos = Position[plot, Line, Infinity];
Clear[line];
(* Copy all the lines to line[n] *)
Array[(line[#] = plot[[Sequence ## Most#linepos[[#]]]]) &,
Total#numlines];
(* Button function *)
AddLabel[label_] := (AppendTo[plot[[1]],
Inset[Framed[label, Background -> White], pt]];
(* Remove buttons for final plain plot *)
plainplot = plot;
bpos = Position[plainplot, Button, Infinity];
Array[(plainplot[[Sequence ## Most#bpos[[#]]]] =
plainplot[[Sequence ## Append[Most#bpos[[#]], 1]]]) &,
Length#bpos]);
(* Substitute all the lines with line buttons *)
Array[(plot[[Sequence ## Most#linepos[[#]]]] = Button[line[#],
AddLabel[lbl[[#]]]]) &, Total#numlines];
Dynamic[EventHandler[plot,
"MouseDown" :> (pt = MousePosition["Graphics"])]]
Here's how it looks. After annotation the plain graphics object can be found set to the 'plainplot' variable.
One approach is to generate the plots separately and then show them together. This yields code that is more like yours than the other post, since PlotMarkers seems to play the way we expect when dealing with one data set. We can get the same coloring using ColorData with PlotStyle. Here's the result:
ff = {Sin, Cos, Tan, Cot};
plots = Table[ListLinePlot[ff[[i]] /# Range[0.1, 10, 0.1],
PlotStyle -> {ColorData[1, i]},
PlotMarkers -> i, Mesh -> 22], {i, 1, Length[ff]}];
(* Delete the spurious asymptote looking thingies. *)
plots = DeleteCases[plots, Line[ll_?(Length[#] < 4 &)], Infinity];
Show[plots, PlotRange -> {-4, 4}]
Are you going to be plotting computable curves or actual data?
If it's computable curves, then it's common to use a plot legend (key).
You can use different dashings and thicknesses to differentiate between the lines on a grayscale printer. There are many examples in the PlotLegends documentation.
If it's real data, then normally the data is sparse enough that you can use PlotMarkers for the actual data points (i.e. don't specify Mesh). You can use automatic PlotMarkers, or you can use custom PlotMarkers including BoxWhisker markers to indicate the various uncertainties.
I am looking to plot something like the whispering gallery modes -- a 2D cylindrically symmetric plot in polar coordinates. Something like this:
I found the following code snippet in Trott's symbolics guidebook. Tried running it on a very small data set; it ate 4 GB of memory and hosed my kernel:
(* add points to get smooth curves *)
addPoints[lp_][points_, \[Delta]\[CurlyEpsilon]_] :=
Module[{n, l}, Join ## (Function[pair,
If[(* additional points needed? *)
(l = Sqrt[#. #]&[Subtract ## pair]) < \[Delta]\[CurlyEpsilon], pair,
n = Floor[l/\[Delta]\[CurlyEpsilon]] + 1;
Table[# + i/n (#2 - #1), {i, 0, n - 1}]& ## pair]] /#
Partition[If[lp === Polygon,
Append[#, First[#]], #]&[points], 2, 1])]
(* Make the plot circular *)
With[{\[Delta]\[CurlyEpsilon] = 0.1, R = 10},
Show[{gr /. (lp : (Polygon | Line))[l_] :>
lp[{#2 Cos[#1], #2 Sin[#1]} & ###(* add points *)
addPoints[lp][l, \[Delta]\[CurlyEpsilon]]],
Graphics[{Thickness[0.01], GrayLevel[0], Circle[{0, 0}, R]}]},
DisplayFunction -> $DisplayFunction, Frame -> False]]
Here, gr is a rectangular 2D ListContourPlot, generated using something like this (for example):
data = With[{eth = 2, er = 2, wc = 1, m = 4},
Table[Re[
BesselJ[(Sqrt[eth] m)/Sqrt[er], Sqrt[eth] r wc] Exp[
I m phi]], {r, 0, 10, .2}, {phi, 0, 2 Pi, 0.1}]];
gr = ListContourPlot[data, Contours -> 50, ContourLines -> False,
DataRange -> {{0, 2 Pi}, {0, 10}}, DisplayFunction -> Identity,
ContourStyle -> {Thickness[0.002]}, PlotRange -> All,
ColorFunctionScaling -> False]
Is there a straightforward way to do cylindrical plots like this?.. I find it hard to believe that I would have to turn to Matlab for my curvilinear coordinate needs :)
Previous snippets deleted, since this is clearly the best answer I came up with:
With[{eth = 2, er = 2, wc = 1, m = 4},
ContourPlot[
Re[BesselJ[(Sqrt[eth] m)/Sqrt[er], Sqrt[eth] r wc] Exp[I phi m]]/.
{r ->Norm[{x, y}], phi ->ArcTan[x, y]},
{x, -10, 10}, {y, -10, 10},
Contours -> 50, ContourLines -> False,
RegionFunction -> (#1^2 + #2^2 < 100 &),
ColorFunction -> "SunsetColors"
]
]
Edit
Replacing ContourPlot by Plot3D and removing the unsupported options you get:
This is a relatively straightforward problem. The key is that if you can parametrize it, you can plot it. According to the documentation both ListContourPlot and ListDensityPlot accept data in two forms: an array of height values or a list of coordinates plus function value ({{x, y, f} ..}). The second form is easier to deal with, such that even if your data is in the first form, we'll transform it into the second form.
Simply, to transform data of the form {{r, t, f} ..} into data of the form {{x, y, f} ..} you doN[{#[[1]] Cos[ #[[2]] ], #[[1]] Sin[ #[[2]] ], #[[3]]}]& /# data, when applied to data taken from BesselJ[1, r/2] Cos[3 t] you get
What about when you just have an array of data, like this guy? In that case, you have a 2D array where each point in the array has known location, and in order to plot it, you have to turn it into the second form. I'm partial to MapIndexed, but there are other ways of doing it. Let's say your data is stored in an array where the rows correspond to the radial coordinate and the columns are the angular coordinate. Then to transform it, I'd use
R = 0.01; (*radial increment*)
T = 0.05 Pi; (*angular increment*)
xformed = MapIndexed[
With[{r = #2[[1]]*R, t = #2[[1]]*t, f = #1},
{r Cos[t], r Sin[t], f}]&, data, {2}]//Flatten[#,1]&
which gives the same result.
If you have an analytic solution, then you need to transform it to Cartesian coordinates, like above, but you use replacement rules, instead. For instance,
ContourPlot[ Evaluate[
BesselJ[1, r/2]*Cos[3 t ] /. {r -> Sqrt[x^2 + y^2], t -> ArcTan[x, y]}],
{x, -5, 5}, {y, -5, 5}, PlotPoints -> 50,
ColorFunction -> ColorData["DarkRainbow"], Contours -> 25]
gives
Two things to note: 1) Evaluate is needed to ensure that the replacement is performed correctly, and 2) ArcTan[x, y] takes into account the quadrant that the point {x,y} is found in.
When plotting a function using Plot, I would like to obtain the set of data points plotted by the Plot command.
For instance, how can I obtain the list of points {t,f} Plot uses in the following simple example?
f = Sin[t]
Plot[f, {t, 0, 10}]
I tried using a method of appending values to a list, shown on page 4 of Numerical1.ps (Numerical Computation in Mathematica) by Jerry B. Keiper, http://library.wolfram.com/infocenter/Conferences/4687/ as follows:
f = Sin[t]
flist={}
Plot[f, {t, 0, 10}, AppendTo[flist,{t,f[t]}]]
but generate error messages no matter what I try.
Any suggestions would be greatly appreciated.
f = Sin[t];
plot = Plot[f, {t, 0, 10}]
One way to extract points is as follows:
points = Cases[
Cases[InputForm[plot], Line[___],
Infinity], {_?NumericQ, _?NumericQ}, Infinity];
ListPlot to 'take a look'
ListPlot[points]
giving the following:
EDIT
Brett Champion has pointed out that InputForm is superfluous.
ListPlot#Cases[
Cases[plot, Line[___], Infinity], {_?NumericQ, _?NumericQ},
Infinity]
will work.
It is also possible to paste in the plot graphic, and this is sometimes useful. If,say, I create a ListPlot of external data and then mislay the data file (so that I only have access to the generated graphic), I may regenerate the data by selecting the graphic cell bracket,copy and paste:
ListPlot#Transpose[{Range[10], 4 Range[10]}]
points = Cases[
Cases[** Paste_Grphic _Here **, Point[___],
Infinity], {_?NumericQ, _?NumericQ}, Infinity]
Edit 2.
I should also have cross-referenced and acknowledged this very nice answer by Yaroslav Bulatov.
Edit 3
Brett Champion has not only pointed out that FullForm is superfluous, but that in cases where a GraphicsComplex is generated, applying Normal will convert the complex into primitives. This can be very useful.
For example:
lp = ListPlot[Transpose[{Range[10], Range[10]}],
Filling -> Bottom]; Cases[
Cases[Normal#lp, Point[___],
Infinity], {_?NumericQ, _?NumericQ}, Infinity]
gives (correctly)
{{1., 1.}, {2., 2.}, {3., 3.}, {4., 4.}, {5., 5.}, {6., 6.}, {7.,
7.}, {8., 8.}, {9., 9.}, {10., 10.}}
Thanks to Brett Champion.
Finally, a neater way of using the general approach given in this answer, which I found here
The OP problem, in terms of a ListPlot, may be obtained as follows:
ListPlot#Cases[g, x_Line :> First#x, Infinity]
Edit 4
Even simpler
ListPlot#Cases[plot, Line[{x__}] -> x, Infinity]
or
ListPlot#Cases[** Paste_Grphic _Here **, Line[{x__}] -> x, Infinity]
or
ListPlot#plot[[1, 1, 3, 2, 1]]
This evaluates to True
plot[[1, 1, 3, 2, 1]] == Cases[plot, Line[{x__}] -> x, Infinity]
One way is to use EvaluationMonitor option with Reap and Sow, for example
In[4]:=
(points = Reap[Plot[Sin[x],{x,0,4Pi},EvaluationMonitor:>Sow[{x,Sin[x]}]]][[2,1]])//Short
Out[4]//Short= {{2.56457*10^-7,2.56457*10^-7},<<699>>,{12.5621,-<<21>>}}
In addition to the methods mentioned in Leonid's answer and my follow-up comment, to track plotting progress of slow functions in real time to see what's happening you could do the following (using the example of this recent question):
(* CPU intensive function *)
LogNormalStableCDF[{alpha_, beta_, gamma_, sigma_, delta_}, x_] :=
Block[{u},
NExpectation[
CDF[StableDistribution[alpha, beta, gamma, sigma], (x - delta)/u],
u \[Distributed] LogNormalDistribution[Log[gamma], sigma]]]
(* real time tracking of plot process *)
res = {};
ListLinePlot[res // Sort, Mesh -> All] // Dynamic
Plot[(AppendTo[res, {x, #}]; #) &#
LogNormalStableCDF[{1.5, 1, 1, 0.5, 1}, x], {x, -4, 6},
PlotRange -> All, PlotPoints -> 10, MaxRecursion -> 4]
etc.
Here is a very efficient way to get all the data points:
{plot, {points}} = Reap # Plot[Last#Sow#{x, Sin[x]}, {x, 0, 4 Pi}]
Based on the answer of Sjoerd C. de Vries, I've now written the following code which automates a plot preview (tested on Mathematica 8):
pairs[x_, y_List]:={x, #}& /# y
pairs[x_, y_]:={x, y}
condtranspose[x:{{_List ..}..}]:=Transpose # x
condtranspose[x_]:=x
Protect[SaveData]
MonitorPlot[f_, range_, options: OptionsPattern[]]:=
Module[{data={}, plot},
Module[{tmp=#},
If[FilterRules[{options},SaveData]!={},
ReleaseHold[Hold[SaveData=condtranspose[data]]/.FilterRules[{options},SaveData]];tmp]]&#
Monitor[Plot[(data=Union[data, {pairs[range[[1]], #]}]; #)& # f, range,
Evaluate[FilterRules[{options}, Options[Plot]]]],
plot=ListLinePlot[condtranspose[data], Mesh->All,
FilterRules[{options}, Options[ListLinePlot]]];
Show[plot, Module[{yrange=Options[plot, PlotRange][[1,2,2]]},
Graphics[Line[{{range[[1]], yrange[[1]]}, {range[[1]], yrange[[2]]}}]]]]]]
SetAttributes[MonitorPlot, HoldAll]
In addition to showing the progress of the plot, it also marks the x position where it currently calculates.
The main problem is that for multiple plots, Mathematica applies the same plot style for all curves in the final plot (interestingly, it doesn't on the temporary plots).
To get the data produced into the variable dest, use the option SaveData:>dest
Just another way, possibly implementation dependent:
ListPlot#Flatten[
Plot[Tan#t, {t, 0, 10}] /. Graphics[{{___, {_, y__}}}, ___] -> {y} /. Line -> List
, 2]
Just look into structure of plot (for different type of plots there would be a little bit different structure) and use something like that:
plt = Plot[Sin[x], {x, 0, 1}];
lstpoint = plt[[1, 1, 3, 2, 1]];