Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Principal component analysis of periodically correlated functional time
  series
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex