Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Indicator function and complex coding for mixed fractional factorial
  designs   In a general fractional factorial design, the $n$-levels of a factor are
coded by the $n$-th roots of the unity. This device allows a full
generalization to mixed-level designs of the theory of the polynomial indicator
function which has already been introduced for two level designs by Fontana and
the Authors (2000). the properties of orthogonal arrays and regular fractions
are discussed.

27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc