mcxload(1)                      USER COMMANDS                       mcxload(1)



  NAME
      mcxload - load matrices and tab files from label format

  SYNOPSIS
      mcxload -abc <fname> (label file) -o <fname> (output file)

      [-abc <fname> (label file)] [-123 <fname> (identifier file)] [-o <fname>
      (output file)] [--stream-mirror (symmetrify, same domain)] [--stream-
      split (assume different domains)] [-re <mode> (edge deduplication mode)]
      [-ri <mode> (image symmetrification mode)] [-etc <fname> (leader 'etc'
      label file)] [-etc-ai <fname> (leaderless 'etc' label file)] [-235
      <fname> (leader '235' label file)] [-235-ai <fname> (leaderless '235'
      label file)] [-write-tab <fname> (save domain tab)] [-write-tabc <fname>
      (save column tab)] [-write-tabr <fname> (save row tab)] [-strict-tab
      <fname> (tab universe)] [-strict-tabc <fname> (tabc universe)] [-strict-
      tabr <fname> (tabr universe)] [-restrict-tab <fname> (tab world)]
      [-restrict-tabc <fname> (tabc world)] [-restrict-tabr <fname> (tabr
      world)] [-extend-tab <fname> (tab launch)] [-extend-tabc <fname> (tabc
      launch)] [-extend-tabr <fname> (tabr launch)] [-123-max <int> (set
      domain range)] [-123-maxc <int> (set column range)] [-123-maxr <int>
      (set row range)] [--stream-log (log transform stream values)] [--stream-
      neg-log (negative log transform stream values)] [--stream-neg-log10
      (negative log-10 transform stream values)] [-stream-tf (transform stream
      values)] [-tf <tf-spec> (transform (not so) final matrix)] [--transpose
      (transpose)] [--write-binary (output binary format)] [--debug (debug)]
      [-h (print synopsis, exit)] [--apropos (print synopsis, exit)]
      [--version (print version, exit)]

  DESCRIPTION
      mcxload reads label input from a file. The format of the file should be
      line-based, each line containing two white-space separated strings
      (labels) and optionally a number separated from the second label by
      whitespace. In the absence of a value, mcxload will use the default
      value 1.0. If a tab is present on an input line, mcxload will assume
      that the tab character is the separator for that line. Lines for which
      the first non-whitespace character is an octothorpe ('#') are skipped.

      mcxload will transform the labels into mcl numerical identifiers and the
      pairs of labels into graph edges or equivalently matrix entries. The
      weight of an edge is the value associated with the associated labels.
      mcxload constructs dictionaries (sometimes just one) that map labels
      onto mcl identifiers as it goes along. It can optionally write these to
      file. In MCL (family) parlance, such a dictionary written to file is
      called a tab file.

      It is possible to specify numerical identifiers directly with the -123
      option. In this case mcxload assumes a canonical domain (cf mcxio) and
      will create the minimal canonical domain that supports the data. Also
      bear in mind the caveat further below.

      It is possible to effectively predeclare labels and thus enforce an a-
      priori known mapping of labels onto numerical identifiers.  Labels
      receive an identifier in the order in which they occur in the input.
      Predeclaring labels can be achieved by having them appear in the desired
      order and setting the edge weight to zero.

      A major mcxload modality is whether the input refers to a single domain
      or to two separate domains. An example of the first is where labels are
      names of people and the value is the extent to which they like one
      another. This encodes a likability graph where all the nodes represent
      people. The reasonable thing to do in this case is to create a single
      dictionary with all names wherever they occur. All tab options (as
      opposed to tabc and tabr) pertain to this scenario and likewise for the
      options --graph and --stream-mirror.

      An example of the second mode is where the first label is again the name
      of a person, the second label is the name of an animal species, and the
      value is the extent to which that person appreciates the species. In
      this case, the reasonable thing to do is to create two dictionaries, one
      for persons and one for species. All tabc and tabr options pertain to
      this scenario. The tabc options always refer to the first label and the
      tabr options always refer to the second label.  The letters c and r
      refer to column and row respectively.  The latter are the names of the
      matrix domains corresponding to the input domains. Refer to mcxio(5).

      A further mcxload modality is whether it constructs dictionaries on the
      fly, or whether it proceeds from a tab file already available.  By
      default mcxload will construct dictionaries on the fly. You need to save
      them with the appropriate -write option(s).  All the strict options read
      a tab file and require any labels in the -abc label input to be present
      in the corresponding tab file. mcxload will then fail in the face of
      absent labels.  All the restrict options simply ignore labels that are
      not found in the corresponding tab file.  The extend options extend the
      existing tab file with labels that are not found.  It presumably only
      makes sense to do so if the corresponding -write options are used as
      well.

      The input stream is deduplicated on a per-node neighbourhood basis using
      the -re option.

      mcxload has a few options to transform or select based on the values in
      the input stream and the values in the constructed matrix. These are
      --stream-log, --stream-neg-log, --stream-neg-log10, -stream-tf and -tf.
      Refer to mcxio(5) for a description of the syntax accepted by the latter
      two options - it is a syntax accepted by a few more mcl siblings.
      Finally it is possible to transpose the final result using the
      --transpose option. Keep in mind that mcxload does not accordingly
      change its idea of row and column domains.

      The final matrix can be symmetrified using the -ri option.

      The -etc and -235 options may be useful for the odd job. These options
      assume a format where all entries for a given column (or equivalently
      all neighbours for a given node) are joined onto a single line. This can
      be useful e.g. to read in externally generated clusterings. The -etc
      options expects label input, whereas the -235 options expects numbers in
      the input that are mapped directly onto mcl numerical identifiers.

      CAVEAT
      Please note that by feeding the line '1000000000 1' to mcxload with
      either of the -235 or -123 options it will try to allocate a matrix with
      one billion columns. This is most likely not what is wanted.  Assuming
      that the input contains fewer than one billion unique labels, one should
      use the label options as described above and below.

      STAGES
      Conceptually, input matrix creation consists of the following stages

       i  Read the input stream, apply -stream-tf transformation
          specification, and optionally push reverse elements (--stream-
          mirror).
      ii  Deduplicate edges in the context of all edges/arcs originating from
          a given node according to the -re option.
     iii  Apply transpose symmetrification according to the -ri option, if
          used.
      iv  Apply -tf transformation specification.

  OPTIONS
      -abc <fname> (label file)
        The file to read label data from. Labels are separated by white-space.
        The labels may optionally be followed by a value (again separated by
        white-space), which is taken as the edge weight between the nodes
        corresponding with the labels. If a tab is present on an input line it
        is presumed to be the separator for that line, including the value if
        present.  Lines for which the first non-blank character is the
        octothorpe ('#') are skipped.

      -123 <fname> (identifier file)
        The file to read numerical data from. The format is the same as for
        label data, but the identifiers are directly mapped onto mcl
        identifiers as described earlier.

      -o <fname> (output file)
        The output file where the constructed matrix is written.

      --stream-mirror (symmetrify, same domain)
        Whenever label1 label2 value is encountered in the input, mcxload
        inserts label2 label1 value in the input stream as well. This option
        implies that both labels belong to the same domain.

      --stream-split (assume different domains)
        This tells mcxload that the two labels belong to different domains.
        The program will create two tab files, one for columns and one for
        rows. This can be used for example to create a logical mapping of gene
        identifiers to species identifiers.

      -re <max|add|mul|first|last> (deduplication mode)
        This specifies how mcxload should collapse repeated entries, that is
        edges for which a value is specified multiple times. This is done
        relative to a single node at a time, taking into account all
        neighbours assembled from the input stream. Note that --stream-mirror
        will result in duplicated entries if the input contains edge
        specifications in both ways.  Also note that first and last might not
        result in symmetric input if only --stream-mirror is used.

      -write-tab <fname> (save domain tab)
        Write the domain to file. It applies to both label types.

      -write-tabc <fname> (save column tab)
        Write the column domain to file. It applies to the first label found
        on each input line.

      -write-tabr <fname> (save row tab)
        Write the column domain to file. It applies to the second label found
        on each input line.

      -strict-tab <fname> (tab universe)
        Read a dictionary from file and require each label to be present in
        the dictionary. mcxload will exit on absentees.

      -strict-tabc <fname> (tabc universe)
        Read a dictionary from file and require the first label on each line
        to be present in the dictionary. mcxload will exit on absentees.

      -strict-tabr <fname> (tabr universe)
        Read a dictionary from file and require the second label on each line
        to be present in the dictionary. mcxload will exit on absentees.

      -restrict-tab <fname> (tab world)
        Read a dictionary from file and only accept input lines (edges) for
        which both labels are present in the dictionary.  mcxload will ignore
        absentees.

      -restrict-tabc <fname> (tabc world)
        Read a dictionary from file and ignore input lines for which the first
        label is absent from the dictionary.

      -restrict-tabr <fname> (tabr world)
        Read a dictionary from file and ignore input lines for which the
        second label is absent from the dictionary.

      -extend-tab <fname> (tab launch)
        Read a dictionary from file and extend it with any label from the
        input not yet present in the dictionary.

      -extend-tabc <fname> (tabc launch)
        Read a dictionary from file and extend it with all first labels from
        the input not yet present in the dictionary.

      -extend-tabr <fname> (tabr launch)
        Read a dictionary from file and extend it with all second labels from
        the input not yet present in the dictionary.

      -123-max <int> (set domain range)
        Numbers starting from <int> will be ignored, and the domain (used for
        both columns and rows) will range from zero up to one less than <int>.

      -123-maxc <int> (set column range)
        Numbers starting from <int> will be ignored in the column domain, and
        the column domain will range from zero up to one less than <int>.

      -123-maxr <int> (set row range)
        Numbers starting from <int> will be ignored in the row domain, and the
        row domain will range from zero up to one less than <int>.

      --stream-log (log transform stream values)
        Replace each entry by its natural logarithm.

      --stream-neg-log (negative log transform stream values)
      --stream-neg-log10 (negative log-10 transform stream values)
        Replace each entry by the negative of its natural logarithm and log-10
        representation, respectively.  This is for example useful to convert
        scores that denote probabilities or p-values such as BLAST scores.

      -stream-tf (transform stream values)
        Transform the stream values as they are read in according to the
        syntax described in mcxio(5).

      -tf <tf-spec> (transform (not so) final matrix)
        Transform the matrix values after deduplication and symmetrification
        according to the syntax described in mcxio(5).

      -ri (<max|add|mul>)
        After the initial matrix has been assembled, it can be symmetrified by
        either of these options. They indicate the operation used to combine
        the entries of the transposed matrix and the original matrix. mul is
        special in that it treats missing entries (which are normally
        considered zero in mcl matrix operations) as one.

      --transpose (transpose)
        Write the transposed matrix to file. This is obviously not useful when
        a symmetric matrix has been generated.

      -etc <fname> (leader 'etc' label file)
      -etc-ai <fname> (leaderless 'etc' label file)
      -235 <fname> (leader '235' label file)
      -235-ai <fname> (leaderless '235' label file)
        The input is read in lines; each line is split on whitespace into
        labels.  For -etc the first label is interpreted as the source node.
        All other labels are interpreted as destination nodes. Currently no
        values are recognized, but this functionality may be introduced in the
        future.  For -etc-ai (auto-increment) all labels are interpreted as
        destination nodes and mcxload automatically creates a source node for
        each line it reads. This option can be useful to read in files
        encoding a clustering, where each line represents a cluster of white-
        space separated labels.

        The -235 options are similar except that the input is not interpreted
        as labels but must consist of numbers that explicitly specify the
        matrix to be built.

      --write-binary (output binary format)
        The output matrix is written in native binary format - refer to
        mcxio(5).

      --debug (debug)
        Among other things, this turns on warnings when restrict tab files are
        used and labels are found to be missing.

  AUTHOR
      Stijn van Dongen.

  SEE ALSO
      mcxio(5), mcxdump(1), mcl(1), mclfaq(7), and mclfamily(7) for an
      overview of all the documentation and the utilities in the mcl family.



  mcxload 1.008, 09-308             4 Nov 2009                        mcxload(1)
