help sqtab                                                      (SJ6-4: st0111)
-------------------------------------------------------------------------------

Title

    sqtab -- Tabulate sequences


Syntax

        sqtab [varname] [if] [in] [, options]

    options               Description
    -------------------------------------------------------------------------
    ranks(numlist)        restrict tabulation on most frequent numlist
    se                    apply same-elements similarity
    so                    apply same-order similarity
    nosort                do not sort according to frequency
    gapinclude            include sequences with gaps in the tabulation
    subsequence(a,b)      use only subsequence between positions a and b
    tabulate_options      any options documented in tabulate
    -------------------------------------------------------------------------


Description

    sqtab displays frequency tables of all sequences in the dataset.
    Sequences are described by listing the first 38 positions of each
    sequence.

    If the optional variable name is specified, a cross tabulation of the
    sequences with the specified variable will be produced.


Options

    ranks(numlist) is used to restrict the output to the most frequent
        sequences. numlist refers to the position of the sequences in the
        sorted frequency table. Hence, ranks(1) refers to the most frequent
        sequence only, whereas ranks(1/10) refers to the 10 most frequent
        sequences. You can also specify ranks(2(2)20).

    se is used to request a frequency table, where similar sequences have
        been grouped together beforehand. The concept for similarity used
        with the option so is called same elements similarity, because it
        treats sequences that consist of the same elements as identical.
        Hence, with this option the sequence B-A-A-B would be treated as
        identical to A-B-B-A, because both sequences consist of the elements
        A and B.

    so is used to request a frequency table, where similar sequences have
        been grouped together beforehand. The concept for similarity used
        with the option so is called same order similarity, because it treats
        sequences where the elements appear in the same order. The sequence
        A-B-B-A would be treated identical to A-B-A-A, because the elements A
        and B appear in the same order in both sequences (first A, then B,
        and then A again).

    nosort changes the default of listing sequences in the table according to
        their frequency. This change is reasonable, because many sequences
        are probably unique. The option nosort turns this default behavior
        off.

    gapinclude is used to include sequences with gaps in the tabulation. The
        default behavior is to drop sequences with gaps from the tabulation,
        because they cannot be used in the program sqom.  The term gap refers
        only to missing values on the element variable within a sequence.
        Sequences with missing values at the beginning and at the end of a
        sequence are included in any case. See sq for details.

    subsequence(a,b) is used to include only the part of the sequence that is
        between position a and b, whereby a and b refer to the position
        defined in the order variable.

    tabulate_options are any of the options documented in tabulate oneway or 
        tabulate twoway.


Author

    Ulrich Kohler, WZB, kohler@wzb.eu


Examples

    . sqtab

    . sqtab, so ranks(1/20)

    . sqtab, se nosort


Also see

    Manual:  [D] tabulate

    Online: sq, sqdemo, sqset, sqdes, sqegen, sqstat, sqindexplot, 
             sqparcoord, sqom, sqclusterdat, sqclustermat