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I know that the command LaunchKernels[] starts up four kernels on my machine:

LaunchKernels[]
{KernelObject[1, "local"], KernelObject[2, "local"], 
 KernelObject[3, "local"], KernelObject[4, "local"]}

I also figured out that the command SetOptions[EvaluationNotebook[], Evaluator -> "xyz"]; should then set the given Notebook to be evaluated on some kernel "xyz", but I cannot find the right syntax for this "xyz" to refer to for instance KernelObject[1, "local"]. What should I write there?

EDIT

This is the relevant command: FrontEndExecute[FrontEndToken["ModifyEvaluatorNames"]]. Create a couple Kernel names and evaluate in parallel.

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2 Answers 2

Reset to default
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LaunchKernels launches subkernels used for parallel calculations. These are not meant to and cannot be set to as the evaluator for a notebook.

To set the evaluator for a notebook, use Evaluation -> Kernel Configuration Options to set up a new kernel, then use Evaluation -> Notebook's Kernel to assign it to the current notebook.

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    $\begingroup$ Can I automatically have Mathematica start a Kernel for each Notebook? I don't like the "everything is shared" approach of Mathematica, so I would love to have a distinct Kernel + Context for each Notebook by default. $\endgroup$
    – Thomas Fankhauser
    Commented Sep 1, 2015 at 9:58
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    $\begingroup$ @ThomasFankhauser I wouldn't bother. Usually licenses allow running only a limited number of kernels, which would set a limit on this. Within that limit, it would be possible to hack something together, but I'm not sure it's worth it as I don't find this type of workflow useful. If you ask a question someone might get interested and write an answer about how to hack it together. Do take a look at using notebook-specific contexts, which create the illusion of localization within notebooks, but use the same kernel. $\endgroup$
    – Szabolcs
    Commented Sep 1, 2015 at 10:35
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    $\begingroup$ Okay thanks for your response. Coming from programming, it's just very unusual to clutter everything together, where you need to wait for evaluations in different notebooks. I think, for sharing the package system should be used and not more. But thanks, you helped me! $\endgroup$
    – Thomas Fankhauser
    Commented Sep 1, 2015 at 11:07
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@ThomasFankhauser

Having all notebooks share all variables can cause subtle problems. I don't know why this is the default and don't see how to change it, but you can change on a per-notebook basis. With the notebook open, go to menu

Evaluation / Notebook's Default Context / Unique to this Notebook (instead of Global)

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    $\begingroup$ The Way Mathematica does it not easy. I asked about a global option to have different Kernel launch by default each time a new notebook is opened. see this question. But no answer. I find Maple's way much much simpler and easier here than how Mathematica does it. In Maple, I set this option once and forget about it. $\endgroup$
    – Nasser
    Commented Jul 3 at 7:30

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