Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A three-dimensional statistical model for imaged microstructures of
  porous polymer films
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg