Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Generalized Hadamard Matrices and Difference Matrices: $Z_6$   We give some very interesting matrices which are orthogonal over groups and,
as far as we know, referenced, but in fact undocumented. This note is not
intended to be published but available for archival reasons.

35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex