The input we need here is a protein sequence.
The output we can get is the sequence's profile and DCA file.

Before running the Perl script (DCA.pl) to generate final Profile and DCA,
you first need to install executable DCA and hhsuite.

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Install DCA
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Using the following command to generate executable DCA
"g++ DCA.cpp -I/path/to/Eigen -o DCA_exe"
/path/to/Eigen is the path to Eigen library. Here we used 3.2.6 version to test. 

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Install hhsuite
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You need to install hhsuite yourself to generate multiple seqnence alignment.
We used 2.0.16 version and database uniprot20_2015_06 to test.

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Usage DCA
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"./DCA.pl (1) (2) (3) (4) (5) (6) (7)"

(1) is the fasta file of target protein sequence.
(2) is the first output file for Profile.
(3) is the second output file for DCA.
(4) is the path to executable DCA of DCA_exe.
(5) is the path to hhsuite.
(6) is the path to hhsuite protein sequence database.
(7) is the path to temporary work folder.