While trying to analyse several different datasets I got what I thought was a good idea: define a "function" that returns a Manipulate object. But this has some problems when larger amounts of data are passed to Manipulate. When the code is first run there is long delay before the manipulate pane is displayed, because the the data gets embedded inside "Body" of Manipulate.
Here is a code snippet that illustrates the problem:
(*Generate some data*)
data = RandomVariate[BinormalDistribution[Abs@Random[]], {5, 10^4}];
histograms = DensityHistogram[#, 30, PerformanceGoal -> "Speed"] & /@ data;
images = Rasterize[#, ImageSize -> Medium] & /@ histograms;
AnalysePlots[plots_] :=
Manipulate[plots[[i]], {i, 1, Length[plots], 1}];
(*Now compare:*)
t = AbsoluteTime[];
AnalysePlots[images] // AbsoluteTiming
AbsoluteTime[] - t
(* ==>3.7091792<---HERE IMAGES GET EMBEDDED*)
t = AbsoluteTime[];
Manipulate[images[[i]], {i, 1, Length[images], 1}] // AbsoluteTiming
AbsoluteTime[] - t
(* ==>0.0312500<---Here they don't*)
Can I somehow choose whether to embed the data (in this case the variable plots) into Manipulate?
When developing the function AnalysePlots it would be nice if I could do something like:
AnalysePlots[images, "Embed"->False]
which would have the benefit of displaying quickly. Then when I've finished AnalyzePlots I would deploy it with:
AnalysePlots[images, "Embed"->True]
which I could then copy and paste to a new notebook, deploy to CDF etc...
(I've already tried SaveDefinitions->False and UnsavedVariables :> {plots})
Answer
This should do the trick:
SetAttributes[AnalysePlots, HoldFirst]
and if you want to embed the images use Evaluate:
AnalysePlots[Evaluate@images]
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