Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Correlation Networks Among Currencies   By analyzing the foreign exchange market data of various currencies, we
derive a hierarchical taxonomy of currencies constructing minimal-spanning
trees. Clustered structure of the currencies and the key currency in each
cluster are found. The clusters match nicely with the geographical regions of
corresponding countries in the world such as Asia or East Europe, the key
currencies are generally given by major economic countries as expected.

25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph