Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Numerical methods for convection-diffusion problems or The 30 years war
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con