Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Improved Fixed-Rank Nystr\"om Approximation via QR Decomposition:
  Practical and Theoretical Aspects
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph