Questions tagged [kernel]
The Kernel is the back-end application thread that does the actual evaluation of all non-graphical expressions. It can be accessed directly through the console but is more commonly working behind the scenes to power the Notebook Interface. Multiple Kernels may be run for parallel computation.
93
questions
66
votes
7
answers
18k
views
Saving data inside a notebook so that I don't have to run it again?
Piggybacking on this, I am somehow not fully convinced that I can't save data generated by a calculation in a mathematica file so that when I re-launch said file, I wouldn't have to run my ...
- 5,321
43
votes
5
answers
4k
views
Aborting evaluation when the memory exceeds a certain limit
Sometimes when generating a lot of data the memory usage shoots beyond its physical realm and my laptop freezes. There is no way to stop Mathematica when this happens. Task manager (or its equivalent ...
- 3,812
16
votes
2
answers
3k
views
Automatically load packages at startup
I'm a physics student and I try to simplify my day with Mathematica. Every time I use Mathematica I need Div[], Grad[], ...
- 163
31
votes
1
answer
1k
views
Why are there two separate MathKernel processes running when I start up Mathematica 9?
When I start the Mathematica 9 Front End, and check the list of running processes, I see two separate MathKernel processes. If I only start the kernel, without a front end, then there's only one ...
- 233k
22
votes
2
answers
635
views
MathKernel doesn't return all Messages
In Mathematica I run this command:
Plot[Sin[x], {x, 1, 15}, GridLines -> error]
It generates a Plot with this error message:
A GridLines specification ...
- 1,412
31
votes
1
answer
940
views
Is the renaming mechanism of `With` flawed?
I'm confused about the renaming mechanism of With:
...
- 2,784
16
votes
1
answer
1k
views
Space-efficient null space of sparse array
I have a roughly 100,000 × 3,000 matrix (as a SparseArray) that I'd like to find the kernel (null space) of.
It has about 500,000 nonzero entries, all -1 or 1.
...
- 305
14
votes
2
answers
569
views
ScheduledTask with scoped variables. Working with timed evaluation
I guess I have to try harder and focus more but timed evaluation always frustrates me.
I will show the issue on simple example of delayed trigger.
...
Kuba♦
- 136k
12
votes
1
answer
619
views
Handling Kernel start. What is a full initialization stack and what place the Autoload has there?
According to: tutorial/WolframSystemSessions
Initialization
On startup, the Wolfram Language kernel does the following:
Performs license management operations.
Runs Wolfram Language ...
Kuba♦
- 136k
21
votes
1
answer
2k
views
Quit the Kernel and start new session automatically
The question is how to quit the kernel, start a new session automatically, and to be able to run such procedure from e.g. Button.
This is especially useful when ...
Kuba♦
- 136k
17
votes
2
answers
518
views
How can I access a variable in one evaluator from another evaluator?
I have two notebooks, each with a different kernel. Is there a way to grab the value of a variable in KernelA from KernelB?
- 31.2k
16
votes
2
answers
396
views
Global context seems to be shared between kernels when using Clear?
I am trying to understand the following behaviour, and determine if it's a bug in Mathematica 10. I am using Mathematica 10.3, and can't reproduce this behaviour under Mathematica 9. The test outlined ...
- 161
17
votes
0
answers
4k
views
Threads vs Cores: How many kernels need to launch in parallel Mathematica?
I have a dual-core intel machine. I would like to test how many parallel local kernels should be launch to get the optimized performance. Knowing that the HyperThreading technology of Intel could run ...
- 1,751
12
votes
3
answers
662
views
Seeking strategies to deploy a function securely without a front end
Background
I have a fuction, which calculates an analytic solution to a multi-dimentional geometry problem.
The function takes a list of real numbers (typically less than a dozen) and outputs a ...
- 14.3k
9
votes
2
answers
1k
views
Keep MathKernel Running In Background - Speed Up Execution Time
Background: I'm running Debian on a remote server with Mathematica installed. I have several dozen small mathematica files that are run in cron jobs at unpredictable intervals and updated based on a ...
- 7,575
7
votes
1
answer
249
views
How does the Kernel know the $Context in a localized notebook
SetOptions[EvaluationNotebook[], CellContext -> Notebook]
$Context
"Notebook$$70$398424`"
And from different ...
Kuba♦
- 136k
24
votes
2
answers
1k
views
Kernel crash after idle in version 10.0
Bug introduced in 10.0.0 and fixed in 10.0.2
In version 10.0, when I leave the Mathematica section idle for some time (of order an hour), the kernel quit automatically. The syntax highlighting is ...
- 7,317
21
votes
1
answer
2k
views
Kernel Management
I would like to run a computation in one NoteBook that will take 2 hours.
Could I assign this Notebook a specific Kernel so I can run computation in other Notebooks ?
- 5,529
16
votes
2
answers
723
views
Detecting kernel initialization
Certain operations do not work during kernel initialization. Code from Kernel/init.m, the Autoload directory, or packages set ...
- 233k
14
votes
1
answer
291
views
Clean package update for API/FormFunctions on Wolfram Cloud
Cross posted on community.wolfram.com (new comments)
TLDR
There is a pool of kernels/sessions available for each user, you don't have control over the pool only over specific kernel you currently ...
Kuba♦
- 136k
7
votes
3
answers
641
views
Can one launch a Player Pro kernel independently of the front end
This question follows on from my earlier one, Seeking strategies to deploy a function securely without a front end.
As it pursues a different track to solve the same problem it seemed distinct enough ...
- 14.3k
7
votes
1
answer
1k
views
Remote Kernel configuration works in v9 but not in v10
I have both v9 and v10 currently installed on my computer (Windows 7). For reasons that are not entirely clear, if I create a new remote kernel in one version, it is accessible to the other; however, ...
- 19.6k
7
votes
1
answer
376
views
CompilationTarget->"C" crashes the kernel
Major deviation from my original post
I realize that the long code I originally had was very discouraging to debug and did not attract any answers. So I have decided to revamp this question ...
- 888
5
votes
1
answer
1k
views
How to connect the front end of one raspberry pi with the kernel of another
I followed the instructions in this howto from wolfram, but I keep getting the error:
...
- 243
52
votes
5
answers
6k
views
Why doesn't Mathematica abort evaluation when I tell it to?
This frequently happens to me. I'll have some code, execute it, and realize it's taking a long time. My PC isn't frozen, and Mathematica itself isn't even frozen: I can select stuff in the notebook, ...
- 3,002
37
votes
3
answers
792
views
How can I evaluate untrusted Mathematica code in a sandbox?
Is there any way to build a sandbox to evaluate untrusted Mathematica expressions in order to prevent them from having (malicious or accidental) harmful side effects?
Context: I'm developing a system ...
- 2,533
22
votes
1
answer
777
views
How to clean up temporary files when the kernel exits?
There are Mathematica packages that must create temporary files to function. If we are implementing such a package ourselves, how can we ensure that the temporary files will get cleaned up when the ...
- 233k
22
votes
2
answers
1k
views
Restarting Mathematica automatically
I run a large computation in a loop. At each cycle of the loop
I produce large arrays that I save on a disk. At each cycle I would like to Quit Mathematica and ...
- 221
16
votes
1
answer
2k
views
Scheduling Mathematica scripts to run from a command line [duplicate]
I want to run Mathematica "jobs" on a daily/weekly basis to do system maintenance and as part of daily processing operations. What is the best way to do this?
- 5,432
15
votes
4
answers
573
views
Obtain input expression from history without evaluating
I typed and evaluated an expression, but deleted it from the notebook. For instance, suppose it was
In[1]:= Round@SessionTime[]
Out[1]= 2
I now want to retrieve ...
- 2,402
13
votes
2
answers
1k
views
Difference between Evaluation ► Quit Kernel and Quit[]
What is the difference between Evaluation ► Quit Kernel and Quit[]?
Both seem to quit the kernel (and clearing all definitions)...
- 651
11
votes
2
answers
475
views
Return partial result when MemoryConstrained aborts NDSolve
I use NDSolve to solve a large set (~400) of coupled ODEs. Sometimes, the memory (~4GB) gets filled up, and my computer becomes impossible to work with, because it ...
- 7,046
11
votes
3
answers
2k
views
Generating figures over remote connection (using terminal)
Recently I've been making movies by having Mathematica create figures and then I combine all of them together using ffmpeg. The problem now is that my macbook is ...
- 6,450
9
votes
1
answer
380
views
Launch Front End from .NET MathKernel and return result to .NET
Is it possible to launch a front end and open a notebook from a .NETLink kernel and return a result from the notebook to .NET?
In the code below "x" appears in the .NET textbox after 10 seconds but ...
- 30.8k
8
votes
3
answers
733
views
Keep kernel running for execution of scheduled task
How can I keep a kernel running until all scheduled tasks have completed? For example upon running the following script bazinga.m:
...
- 5,100
7
votes
1
answer
3k
views
Improving NDSolve speed for heavily stiff problems
Having looked around the intergoogles and Mathematica.SE, I thought I'd pose a question with a minimum working example.
Here is the situation I am trying to improve:
I am solving a 4th order non ...
- 5,321
6
votes
1
answer
935
views
Mathematica versions 10 and 11 fonts are broken on Linux
Any clues on how to fix the fonts? It seems the font kerning is wrong. It happens both in graphics and in all sorts of text styles...
This happens with Mathematica system fonts but also with certain ...
- 325
5
votes
1
answer
332
views
Mma11 on Windows: Forgetful kernel?
I am seeing the following issue on Windows 7 x64, with the new Mma 11:
I define the simple function below, and evaluate it. The first time is fine, but after that the kernel seems to have forgotten ...
- 4,129
4
votes
1
answer
240
views
ListVectorPlot crashes kernel after two evaluations
I am currently trying to produce many plots by using ListVectorPlot, but every time I re-evaluate my code, the kernel crashes. I have set $HistoryLength=0 and ...
- 95
2
votes
0
answers
359
views
Kernel crash after repeated use of NDSolve
I am trying to solve the Einstein-Klein-Gordon system (equations below) for different piecewise potentials but the kernel keeps crashing after repeated use of NDSolve.
Apparently, everything works ...
- 21
2
votes
1
answer
545
views
Render dynamic Graphics objects static
As was discussed in the comments of another question (MathLink Graphical Output (Plots) to File), Graphcis objects produced by commands such as ...
- 1,660
1
vote
2
answers
287
views
Strange evaluation of an sum involving binomial coefficients
I stumbled upon this problem while playing with Mathematica 10. Can anyone help me explain the following behaviour?
I define a sum
...
- 11
38
votes
2
answers
3k
views
What information is sent to Wolfram Research when loading or working with Mathematica?
Recently I am told that information unknown to the user is sent to Wolfram Servers. Is there any truth behind it ? I was told that more than just an IP address of the user is sent to them and that ...
- 341
25
votes
4
answers
8k
views
When running Mathematica from a Linux terminal, how can I prevent a script from terminating upon logout?
I am running Mathematica on a remote Linux cluster, by the terminal, using the math command. (I do not have access to a terminal GUI. For example, when I type the ...
- 10.4k
23
votes
3
answers
4k
views
Unsaved notebook is crashing: is there any way I can save the state of the MathKernel before I kill it?
So I'm in the middle of generating some plots and all of the sudden the frontend goes dead and I haven't saved my work. I'm using Mathematica 8 in MacOS X.
The MathKernel process is still running and ...
20
votes
2
answers
2k
views
How to restart computation when kernels die?
When an important process needs to be kept alive, there are monitoring tools to restart them if they die (e.g. god tasks in ruby), in my case I have an overnight scraping task that I need to have done ...
- 31.2k
18
votes
3
answers
5k
views
The most simple Manipulate freezes the notebook on v10.1
I realize this won't be a particularly clear question. As I'm not able myself to find a pattern for the problem I'm talking about I won't be able to give enough informations to make it fully ...
- 7,543
15
votes
1
answer
273
views
All value types for a symbol?
Robby Villegas here shows a nice way to see all the types associated with a symbol. He sets a symbol, valueTypes, to an explicit list of the values types in ...
- 8,651
13
votes
3
answers
413
views
Suspecting bug in Parallel Framework
I've reduced my actual problem to:
ParallelEvaluate[
Module[{slot=1},
Slot[slot]
]
]
gives error messages that I think shouldn't be there. It seems I can ...
- 3,912
13
votes
3
answers
937
views
Handling Kernel quit
One can use $Epilog to do something when the Kernel is quit or put an end.m file next to the ...
Kuba♦
- 136k