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.

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28
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2answers
883 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 ...
27
votes
4answers
1k 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 ...
27
votes
4answers
2k 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 ...
22
votes
5answers
9k views

How do I clear all user defined symbols?

Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
19
votes
1answer
495 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 ...
19
votes
2answers
1k 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 ...
18
votes
1answer
380 views

Kernel crash after idle in version 10.0

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 gone and the variables that has defined before ...
15
votes
2answers
288 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 ...
14
votes
2answers
240 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?
12
votes
4answers
1k 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 ...
12
votes
1answer
573 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 ?
11
votes
3answers
299 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 ...
11
votes
1answer
491 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. ...
10
votes
1answer
349 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?
10
votes
2answers
571 views

Evaluator option for Mathematica Scripts

I have mathematica with many additional kernels besides Local ( e.g., core1, core2, core3, core4 ... ) added through Kernel Configuration Options. I have been running multiple copies of a simulation ...
10
votes
2answers
170 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 ...
9
votes
2answers
296 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 ...
8
votes
2answers
270 views

Does Mathematica on Mac OS use virtualization for certain functions?

I'm evaluating this code in Mathematica 8.0.0 on Mac OS X 10.6.8: ...
7
votes
2answers
111 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 ...
7
votes
3answers
895 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 ...
7
votes
2answers
716 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[], ...
7
votes
1answer
487 views

How to stop the Kernel from running wild?

How to abort or stop this (accidently large defined) SparseArray production? s = N[SparseArray[Table[{2^i, 4} -> i, {i, 30}]]] Alt+. or Alt+, seem to give ...
7
votes
1answer
183 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. ...
7
votes
1answer
119 views

Importing parts of Packages

Some programming languages offer the possibility of importing a single function from a library, as in from x import y I'm looking to import only one function ...
7
votes
1answer
588 views

Creating and editing new stylesheets

I'm trying to create a stylesheet, but the process has become painful. I'm sure that this has to do something with resetting something in Mathematica everytime I make changes to the stylesheet. To ...
6
votes
2answers
271 views

Why LibraryLink function crashes at a second time?

I'm trying link one of Lapack's function to Mathematica through LibraryLink, and the Library function works great at the first execution but crashes at the second time. Here is the code (modified ...
6
votes
2answers
322 views

Using NotebookDirectory in batch-mode

I am running Mathematica via the terminal (Linux) and my .m-script contains the command: ...
6
votes
1answer
299 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 ...
6
votes
1answer
104 views

ClearAll[“Global`*”] stops working with Context set to 'unique to this Notebook'

I just changed my default notebook context to 'unique to this Notebook' so that variables don't roll across numerous open notebooks. Doing this, however, made the command ClearAll["Global*"] stop ...
6
votes
1answer
320 views

Accessing data on local machine from remote kernel

I have a remote kernel on a server that I would like to use to process some data. The connection works, i.e, I'm able to use the local front end and the remote kernel. However, I cannot figure out how ...
6
votes
1answer
325 views

Using “Raw MathLink Connections” to create a “Kernel Object”

Mathematica 8.0.0: I am stuck trying to get a Mathematica Mathlink connection from my Windows computer working that should connects to Linux over network (or vice versa) and then launches a Kernel on ...
6
votes
2answers
88 views

Communication between local kernels

this is my first post but you have already helped me so many times that I have to start by saying thanks a lot! I have a really long calculation to do, and I have used the Evaluation->Kernel ...
6
votes
0answers
185 views

Keyboard issues with Mathematica 9.0.1 for Linux

After working for a while with Manipulate function and increasing the number of variables to be manipulated, keyboard stops working properly in the Notebook. It ...
6
votes
0answers
136 views

In .NET/Link, how do I not open multiple kernels?

I'm writing an ASP.NET page intended for multiple users. On the backend we have datatypes that are primarily mathematical, and interact with Mathematica for string-to-double evaluations, among ...
5
votes
3answers
908 views

Remote Mathkernel: SSH encountered a networking error while launching kernel Error code = 1

I have a problem concerning the connection to a remote kernel via ssh on a vpn. I found a working configuration in this question: Connection to remote kernel can not be established - No specific ...
5
votes
3answers
248 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 ...
5
votes
1answer
155 views

Why is $ProcessorCount different than the selected number of cores in PBS?

By using ParallelTable and submitting my Mathematica code to a cluster, I noticed that it was enhancing the speed even when I selected a single core in a single ...
5
votes
0answers
139 views

Context “Unique to This Notebook” makes variables black even if they're not defined?

I'm trying to use this technique to keep variables separated between different notebooks. It seems to be working fine, except that variables turn black as soon as they are evaluated — any ideas why ...
4
votes
2answers
169 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: ...
4
votes
1answer
506 views

How is the Mathematica kernel structured internally, and how does evaluation work?

There is so much information available for Java--the internal details of (for example) the JVM memory manager are well-documented, and the performance considerations arising from its interaction with ...
4
votes
1answer
492 views

Connection to remote kernel can not be established - No specific error shown

I was trying to set up a remote kernel using Mathematica 8, a Debian server and a Mac OSX 10.8 client. First I configured a VPN connection between server and client and went through all the basic ...
4
votes
1answer
64 views

How can I kill one evaluator from another?

I have a kernel named A in one notebook and other notebook with kernel B, how can I kill B from A?
4
votes
2answers
154 views

Why does Mathematica stop when run in the background in command line mode?

If I try to start a Mathematica script in the background from the command line, like this: math -script someFile.m & then the process gets automatically ...
4
votes
2answers
486 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 ...
4
votes
1answer
576 views

Forget past outputs to free memory

While tinkering with a notebook that loads a large chunk of data in memory, I noticed that if I run it multiple times, the past chunks reside in memory. I understand that the reason (or one of) for ...
4
votes
0answers
55 views

How to save the result in the Notebook (.nb) and shut down the computer when the calculation is done

I have a notebook(.nb) which its calculation is time-consuming and long. I can not observe it if the calculation is done or not. Therefore, I want to : (1) Save the results in the notebook(.nb) ( I ...
4
votes
0answers
72 views

Suspend computation so it can be resumed even after the PC is rebooted

Sometimes a computation takes a long time. But when I sleep in the night, I want to shutdown my PC. Next morning when I wake, I want to start Mathematica and resume the computation. If you are ...
4
votes
0answers
95 views

MathKernel with `-noprompt` hangs indefinitely when converting simple TeX expression

If I enter MathKernel -noprompt -run 'ToExpression["1", TeXForm]; Exit[]' the kernel hangs, apparently while running TeX.exe ...
4
votes
0answers
209 views

Why FrontEnd`KernelExecute doesn't work in KeyEventTranslations.tr?

Which commands can you put in KeyEventTranslations.tr ? There is an extensive list of FrontEndTokens, but what else can you use? Why something like this doesn't ...
3
votes
2answers
169 views

Reasoning about Degree of Polynomial

Apologies if this is outside of the realm of Mathematica -- I'm still trying to figure out the limits of how expressive Mathematica is (and how much of my work can be automated). Suppose I define the ...