Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: DuMu$^\text{x}$ 3 -- an open-source simulator for solving flow and
  transport problems in porous media with a focus on model coupling   We present version 3 of the open-source simulator for flow and transport
processes in porous media DuMu$^\text{x}$. DuMu$^\text{x}$ is based on the
modular C++ framework Dune (Distributed and Unified Numerics Environment) and
is developed as a research code with a focus on modularity and reusability. We
describe recent efforts in improving the transparency and efficiency of the
development process and community-building, as well as efforts towards quality
assurance and reproducible research. In addition to a major redesign of many
simulation components in order to facilitate setting up complex simulations in
DuMu$^\text{x}$, version 3 introduces a more consistent abstraction of finite
volume schemes. Finally, the new framework for multi-domain simulations is
described, and three numerical examples demonstrate its flexibility.

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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
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The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
4
The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
2
The categories of this paper are: math
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-th