Manipulate
Manipulate[expr_, {u_Symbol, min_, max_}..]Manipulate[expr_, {{u_Symbol, initial_}, min_, max_}..]Manipulate[expr_, {{u_Symbol, initial_}, min_, max_, step_}..]Manipulate[expr_, {{u_Symbol, initial_, label_String}, min_, max_, step_}..]Manipulate[expr_, {{u_Symbol}, values_List}..]Manipulate[expr_, {{u_Symbol, initial_}, values_List}..]Manipulate[expr_, {{u_Symbol, initial_, label_String}, values_List}..]generates a version of expr with controls added to allow interactive reevaluation.
Manipulate can be used on any Wolfram expression. Graphics or images passed as expr or part of it will be automatically optimized using JIT transpiler if possible. This provides an immediate mode for a user to construct interactive widgets.
By its nature, all interactivity in WLJS Notebooks is implemented in retained mode, while Manipulate is a wrapper over low-level building blocks such as Offload, InputRange, etc., with a diff algorithm used to optimize evaluation of changes. For frequently changing data or complex visuals, we still recommend using these low-level building blocks.
Consider also ManipulatePlot and ManipulateParametricPlot for basic interactive curve plotting.
Examples
Here is a basic example involving symbolics:
Manipulate[Series[Sinc[x], {x, 0, n}], {n, 1, 5, 1}]Here are a few examples with Plot expressions that effectively use JIT:
Manipulate[
Plot[Sin[a x + b], {x, 0, 6}], {{a, 2, "Multiplier"}, 1,
4}, {{b, 0, "Phase Parameter"}, 0, 10}, ContinuousAction->True]Manipulate[Plot[1.0 + Sin[w] Sin[x + w],{x,0,5Pi}, Epilog->{
Red, Point[{8.0, 1.0 + Sin[w] Sin[8.0 + w]}]
}], {w,0,Pi}, ContinuousAction->True]Another example that solves an ODE on the fly:
Manipulate[
Plot[Evaluate[
y[t] /. First[
NDSolve[ {y''[x] == -x y[x], y[0] == a, y'[0] == b},
y, {x, 0, 4}]]], {t, 0, 4},
Epilog -> {Point[{4, 1/2}], Green, Arrow[{{0, a}, {1, b + a}}], Red,
Point[{0, a}]}, PlotRange -> 3],
{{a, 1}, -3, 3},
{{b, 0}, -3, 3}]3D plot example:
Manipulate[Plot3D[Sin[n x] Cos[n y], {x,-1,1}, {y,-1,1}], {n, 1, 5, 0.3}, ContinuousAction->True]Images:
img = ImageResize[ExampleData[ExampleData["TestImage"] // Last], 350];
Manipulate[
ImageAdjust[img, {c,a}],
{{c, 0},0,5,0.1},
{{a, 0},0,5,0.1},
ContinuousAction->True
]Here is an example with mixed symbolics and graphics:
Manipulate[
Row[{
"m", "==", MatrixForm[m],
StreamPlot[Evaluate[m . {x, y}], {x, -1, 1}, {y, -1, 1},
StreamScale -> Large, ImageSize -> Small
]
}], {{m, ((*GB[*){{1(*|*),(*|*)0}(*||*),(*||*){0(*|*),(*|*)2}}(*]GB*))}, { ((*GB[*){{1(*|*),(*|*)0}(*||*),(*||*){0(*|*),(*|*)2}}(*]GB*)) -> "Nodal source", ((*GB[*){{1(*|*),(*|*)1}(*||*),(*||*){0(*|*),(*|*)1}}(*]GB*)) -> "Degenerate source", ((*GB[*){{0(*|*),(*|*)1}(*||*),(*||*){-1(*|*),(*|*)1}}(*]GB*)) -> "Spiral source", ((*GB[*){{-1(*|*),(*|*)0}(*||*),(*||*){0(*|*),(*|*)-2}}(*]GB*)) -> "Nodal sink", ((*GB[*){{-1(*|*),(*|*)1}(*||*),(*||*){0(*|*),(*|*)-1}}(*]GB*)) -> "Degenerate sink", ((*GB[*){{0(*|*),(*|*)1}(*||*),(*||*){-1(*|*),(*|*)-1}}(*]GB*)) -> "Spiral sink", ((*GB[*){{0(*|*),(*|*)1}(*||*),(*||*){-1(*|*),(*|*)0}}(*]GB*)) -> "Center", ((*GB[*){{1(*|*),(*|*)0}(*||*),(*||*){0(*|*),(*|*)-2}}(*]GB*)) -> "Saddle"}}] Options
ContinuousAction
By default, this is False, which means that any update happens after the user's action, not before.
"ControlsLayout"
By default, this is "Vertical". Another possible value is "Horizontal".
PerformanceGoal
By default, this is "Speed", which involves the JIT Transpiler. Change it to any other value to disable it completely.
"JITFeature"
By default, this is True, which involves the JIT Transpiler. If either PerformanceGoal or "JITFeature" is set to a non-default value, the JIT transpiler will be disabled.
Appearance
By default, this is "Default". Set it to None to remove the frame and info boxes.
"UpdateFunction"
Allows to alter the expression, prevent default actions or cause side-effects upon update. The following return values are expected
Function[input,
(* side effects *)
(* RETURN *)
True <- accept change
False <- prevent default
_String <- will be written instead
]One can completely bypass the default reevaluation and use side-effects only
Module[{r},
Manipulate[Graphics[Disk[{0,0}, r//Offload]],
{{radius, 1}, 0,1},
"UpdateFunction" -> Function[value,
r = value;
False (* always reject *)
]
]
]However, we do recommend to use InputRange directly instead of Manipulate for such cases.
JIT Transpiler
Manipulate, as well as Animate, uses a diff algorithm that detects and tries to convert manipulated expressions to more optimized ones that utilize granular updates. If the diff algorithm fails, it will use full reevaluation and update the shown expression accordingly.
Our transpiler does not cover all symbols and is limited to the following for now:
Line,Point,Polygon,Tube,Arrow,Disk,Circle,Sphere,Cuboid,Rectangle,TextGraphicsComplexin the context ofGraphics3DImagePlotLabelin the context ofGraphicsLineLegend,PointLegend,SwatchLegend
which is a good subset to cover the output produced by Plot, Plot3D and many others standard functions. What will not be supported in the near future:
PlotRangemutations are ignored- adding/removing
Line,Pointand etc primitives at runtime leads to deoptimization - changing color or opacity leads to full reevaluation
Tips for better performance
If you still want to use Manipulate on some complex expressions, there are some tricks to avoid JIT engine failures:
- Try to keep the number of curves/traces/polygons expressions the same if possible. Try not to add new entities to your graphs.
PerformanceGoal->"Speed"is also a good option for 3D plots.Mesh->Nonemight also help.PlotRange->Fullor set it manually, it can help to avoid fragmentation of line segments- Avoid changing colors, opacity
Debugging
To see the latest message of JIT failure - evaluate the symbol:
CoffeeLiqueur`Extensions`Manipulate`Diff`$lastJITFailurePortability
Same as for Animate, Manipulate widgets can be shared as MDX or HTML in automatic mode.
Keep the number of possible states determined by all your sliders and selection boxes below 500-600.
MMAView
MMAView wrapper allows to use native Wolfram Engine rendering engine for manipulated expressions. It uses a parallel kernel to rasterize the provided expression and stream updates to the frontend.
Manipulate[Plot3D[Sin[n x] Cos[n y], {x,-1,1}, {y,-1,1}], {n, 1, 5, 1}] // MMAViewIt literally streams uncompressed raster images in real-time. Please do not overuse it