Skip to main content

front end - How to see Monitor temporary cell with ParallelSubmit?


I have a function to load large files into a "HSQL(Standalone)" database for processing that uses Monitor to update the interface on the progress and status of the upload.


loadBigFile[t_Integer?Positive, steps_Integer?Positive] :=
 Module[{stepProgress = 0},
  Monitor[
   While[stepProgress < steps,

    (* Read batch and load to db *)
    Pause[t];
    stepProgress += 1
    ],
   Column[{StringRiffle[ToString /@ {stepProgress, steps}, " of "],
     ProgressIndicator[stepProgress, {0, steps}]},
    Alignment -> Center]
   ];
  stepProgress
  ]


loadBigFile is just to demonstrate the issue.


loadBigFile[1, 10]
(* 10 *)

enter image description here


This process takes 30+ minutes to load each file. I would like to concurrently load these files to reduce the wait time by using ParallelSubmit.


k = LaunchKernels[2];
DistributeDefinitions[loadBigFile];
{f1, f2} = {ParallelSubmit[loadBigFile[1, 5]], ParallelSubmit[loadBigFile[1, 9]]}


enter image description here


When I execute WaitAll the EvaluationObjects do run concurrently. However, instead of a monitor temporary cell for each of them I get a front end error from each kernel they are running on.


WaitAll[{f1, f2}]
CloseKernels[k];

enter image description here


(* {5, 9} *)



FrontEndObject::notavail: A front end is not available; certain operations require a front end.



How do I get the monitor temporary cells to show in the notebook for each EvaluationObject running? Or is there another method I should use for concurrent execution with Monitor?



Answer



From the link in the comment above I have devised a solution included here for ParallelSubmit specific searches.


Monitor can not be used so I make a progress function that will assist with the visual status update.


progress[current_, total_] :=
 Column[{StringRiffle[ToString /@ {current, total}, " of "],
   ProgressIndicator[current, {0, total}]},
  Alignment -> Center]


I use a status Association to hold the status updates as it makes the code more readable than using a list as with other solutions. The loadBigFile function has to change slightly.


loadBigFile[t_Integer?Positive, steps_Integer?Positive] :=
 Module[{stepProgress = 0},
  status[[Key[$KernelID]]] = <|
    "File" -> "File " <> ToString@RandomInteger[100],
    "Monitor" -> progress[stepProgress, steps]
    |>;
  While[stepProgress < steps,
   (* Read batch and load to db *)

   Pause[t];
   stepProgress += 1;

   (* Update status *)
   status[[Key[$KernelID], "Monitor"]] = progress[stepProgress, steps];
   ];

  status[[Key[$KernelID], "File"]] = status[[Key[$KernelID], "File"]] <> " done.";
  stepProgress
  ]


The Keys of the Association are the $KernelID and each has a "File" and "Monitor" key. loadBigFile updates these as it progresses.


k = LaunchKernels[2];

status = Association @@ 
     ParallelTable[$KernelID -> <|"File" -> "", "Monitor" -> ""|>, {i, $KernelCount}]
(* <|43 -> <|"File" -> "", "Monitor" -> ""|>, 42 -> <|"File" -> "", "Monitor" -> ""|>|> *)

Distribute the definitions and variables


DistributeDefinitions[progress, loadBigFile];

SetSharedVariable[status];

ParallelSubmit the jobs.


{f1, f2} = {ParallelSubmit[loadBigFile[1, 5]], ParallelSubmit[loadBigFile[1, 9]]}

enter image description here


PrintTemporary with Dynamic is used instead of Monitor. This accesses the status association to display.


PrintTemporary[
  Dynamic[Row[
    Riffle[Column[#, Alignment -> Center] & /@ 

      Query[Values, Values]@Select[#"Monitor" =!= "" &]@status, Spacer[5]]]]];
WaitAll[{f1, f2}]

enter image description here


Both have status displayed and updated concurrently.


Clean up.


UnsetShared[progress, loadBigFile, status];
CloseKernels[k];

Hope this helps.



Comments

Post a Comment

Popular posts from this blog

plotting - Filling between two spheres in SphericalPlot3D

Manipulate[ SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, Mesh -> None, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], {n, 0, 1}] I cant' seem to be able to make a filling between two spheres. I've already tried the obvious Filling -> {1 -> {2}} but Mathematica doesn't seem to like that option. Is there any easy way around this or ... Answer There is no built-in filling in SphericalPlot3D . One option is to use ParametricPlot3D to draw the surfaces between the two shells: Manipulate[ Show[SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], ParametricPlot3D[{ r {Sin[t] Cos[1.5 Pi], Sin[t] Sin[1.5 Pi], Cos[t]}, r {Sin[t] Cos[0 Pi], Sin[t] Sin[0 Pi], Cos[t]}}, {r, 1, 2 - n}, {t, 0, Pi}, PlotStyle -> Yellow, Mesh -> {2, 15}]], {n, 0, 1}]
Post a Comment
Read more

plotting - Plot 4D data with color as 4th dimension

I have a list of 4D data (x position, y position, amplitude, wavelength). I want to plot x, y, and amplitude on a 3D plot and have the color of the points correspond to the wavelength. I have seen many examples using functions to define color but my wavelength cannot be expressed by an analytic function. Is there a simple way to do this? Answer Here a another possible way to visualize 4D data: data = Flatten[Table[{x, y, x^2 + y^2, Sin[x - y]}, {x, -Pi, Pi,Pi/10}, {y,-Pi,Pi, Pi/10}], 1]; You can use the function Point along with VertexColors . Now the points are places using the first three elements and the color is determined by the fourth. In this case I used Hue, but you can use whatever you prefer. Graphics3D[ Point[data[[All, 1 ;; 3]], VertexColors -> Hue /@ data[[All, 4]]], Axes -> True, BoxRatios -> {1, 1, 1/GoldenRatio}]
Post a Comment
Read more

plotting - Mathematica: 3D plot based on combined 2D graphs

I have several sigmoidal fits to 3 different datasets, with mean fit predictions plus the 95% confidence limits (not symmetrical around the mean) and the actual data. I would now like to show these different 2D plots projected in 3D as in but then using proper perspective. In the link here they give some solutions to combine the plots using isometric perspective, but I would like to use proper 3 point perspective. Any thoughts? Also any way to show the mean points per time point for each series plus or minus the standard error on the mean would be cool too, either using points+vertical bars, or using spheres plus tubes. Below are some test data and the fit function I am using. Note that I am working on a logit(proportion) scale and that the final vertical scale is Log10(percentage). (* some test data *) data = Table[Null, {i, 4}]; data[[1]] = {{1, -5.8}, {2, -5.4}, {3, -0.8}, {4, -0.2}, {5, 4.6}, {1, -6.4}, {2, -5.6}, {3, -0.7}, {4, 0.04}, {5, 1.0}, {1, -6.8}, {2, -4.7}, {3, -1.
Post a Comment
Read more