The software package HiFiX implements the novel algorithm for HIgh FIdelity Clustering of Sequences.

To tackle the challenge of finding proteins families, we model the all-against-all comparison between proteins by a similarity network.
HiFiX combines network topology analysis where sequence similarity is seen as a social relationship, multiple alignment quality measurement and model selection theory.

HiFiX supports multiprocessing and is therefore fast enough to be used in practice on large amounts of data.

HiFiX is already included in the experimental pipeline for HOGENOM.


SiLiX is licensed under the General Public License.


You can download the latest version HERE.


HiFiX was succesfully tested on Linux (Ubuntu up to 14.04, Debian Wheezy 7.0) and Mac OSX (Darwin 10.5.8)

HiFiX does not work with Python 3.x, Python 2.X required Python modules (already installed by default in Python >=2.7):


(for local install, set the PYTHONPATH variable to /path_to/module)

Auxiliary software packages (installation required)

  • SiLiX (version >= 1.2.10)
  • HMMER3
  • Louvain : for this program, there is no proper install procedure. First uncompress this archive and go to the Community_BGLL_CPP directory. Compile with make (NB:on MacOS only, create a dummy file with touch malloc.h, and compile with make CFLAGS+="-I."). Then we suggest three solutions:
  • [RECOMMENDED] copy manually the binaries community, convert and hierarchy in your PATH (in /usr/local/bin for example)
  • add the /path_to/Community_BGLL_CPP directory to your PATH (export PATH=$PATH : /path_to/Community_BGLL_CPP)
  • [EASY] pass the /path_to/Community_BGLL_CPP directory to HiFiX by command line (in this way, the above test procedure will fail... don’t panic)


Compilation and installation are compliant with the Python standard procedure

tar zxvf hifix-x.x.x.tar.gz
cd hifix-x.x.x
python setup.py test
python setup.py install

(for local install, add the flag —prefix /path_to/hifix and set PYTHONPATH= /path_to/hifix/lib/python2.x/site-packages)


(see also Tutorial section)

  • THE EASY WAY (most users):

To get information or help:

hifix --help


The user provides a fasta file FASTAFILE (*less than 256 characters per line* and no "U" character [to be replaced by "X"]), the result file of SiLiX clustering FNODESFILE and the network file NETFILE obtained with SiLiX :


If using a multiprocessor machine with NBPROCS cores, it is valuable to specify the option :

hifix -t <NBPROCS> ...

If you have a /dev/shm directory (shared memory), it is recommended to use it (gains of performance) :

hifix -d /dev/shm ...


List of pairs in format "family_id sequence_id" where :

  • sequence_id are those of FASTAFILE
  • family_id are build from the prefix of FASTAFILE (prefix.fasta) followed by a unique tag such as
    • "_i_j" if family j was deduced from SiLiX pre-family i
    • "_i" if SiLiX pre-family i was conserved


seq_1_1 id1
seq_1_2 id2
seq_2 id3


The user provides a fasta file and the result file(s) of a all-against-all BLAST search in tabular format. It is now necessary to use SiLiX as a preliminary step, with —net option (see Documentation) :

silix seq.fasta blastall.out --net > seqSLX.fnodes

A file blastall.net has been generated.
NB : if you use the MPI version of SiLiX (with mpirun), you get multiple .net files that you need to concatenate into in single .net file.

The user can now use hifix :

hifix seq.fasta blastall.net seqSLX.fnodes > seqHFX.fnodes

See also example files in the data/ directory of the package.


Due to mafft-profile requirements, it may be necessary to run HiFiX on computers with more than 2 GB RAM. If SiLiX results displays pre-families larger than 15000 sequences, we recommend using more than 4 GB RAM.
Please note that, if HiFiX runs on multiple cores (option -t), the memory requirements are additive with the number of processes.

  • THE HARD WAY (for very large datasets, if you have cluster or grid facilities, please contact us) :

The user must program a pipeline with independent tasks (hifixcore program) distributed and submitted to a scheduler, like this :

silix .....
silix-split ....
for all <FASTAFILE> <NETFILE> do
    hifixcore  <FASTAFILE> <NETFILE>  (job to be submitted)

HiFiX is developed by :

If you use HiFiX in a published work, please cite the following reference :

Miele,V., Penel, S., Daubin,V., Picard,F., Kahn,D. and Duret,L., High-quality sequence clustering guided by network topology and multiple alignment likelihood, Bioinformatics 2012

HiFiX is also mentionned in :

Dessimoz,C., Gabaldon,T., Roos, D.S., Sonnhammer,E., Herrero,J. and the Quest for Orthologs Consortium (incl. Miele,V.), Toward Community Standards in the Quest for Orthologs, Bioinformatics 2012

For any bugs, information or feedback, please contact:

Vincent Miele

- Download multidom.fasta and blastmultidom.out

  • .fasta : sequences in FASTA format (less than 256 character per line and no "U" character [to be replaced by "X"])
  • .out : BLAST results in tabulated format
  • .fnodes : list of pairs in format "family_id sequence_id"

- Build pre-families with silix

silix multidom.fasta blastmultidom.out --net > multidom_SLX.fnodes

  • 8 pre-families displayed in multidom_SLX.fnodes
PNG - 4.6 ko
  • blastmultidom.net is generated and corresponds to the similarity network represented below
PNG - 10.6 ko

NB : if you use the MPI version of SiLiX (with mpirun), you get multiple .net files that you need to concatenate into in single .net file.

- Build high-quality families with hifix

hifix multidom.fasta blastmultidom.net multidom_SLX.fnodes > multidom_HFX.fnodes

  • 9 families displayed in multidom_HFX.fnodes
PNG - 4.2 ko
  • if n are processors avalaible, use option

-t n