Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Spatial risk mapping for rare disease with hidden Markov fields and
  variational EM
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ