dbcolpercentile - Man Page

compute percentiles or ranks for an existing column

Synopsis

    dbcolpercentile [-rplhS] column

Description

Compute a percentile of a column of numbers. The new column will be called percentile or rank. Non-numeric records are handled as in other programs.

If the data is pre-sorted and only a rank is requested, no extra storage is required. In all other cases, a full copy of data is buffered on disk.

Options

-p or --percentile or --mode percentile: Show percentile (default). Percentile is the percentage of the cumulative values at or lower than the current value, relative to the total count.
-P or --rank or --nopercentile or --mode rank: Compute ranks instead of percentiles.
--fraction: Show fraction (percentage, except between 0 and 1, not cumulative fraction).
-a or --include-non-numeric: Compute stats over all records (treat non-numeric records as zero rather than just ignoring them).
-S or --pre-sorted: Assume data is already sorted. With one -S, we check and confirm this precondition. When repeated, we skip the check.
-f FORMAT or --format FORMAT: Specify a printf(3)-style format for output statistics. Defaults to %.5g.
-T TmpDir: where to put tmp files. Also uses environment variable TMPDIR, if -T is not specified. Default is /tmp.

Sort specification options (can be interspersed with column names):

-r or --descending: sort in reverse order (high to low)
-R or --ascending: sort in normal order (low to high)
-n or --numeric: sort numerically (default)
-N or --lexical: sort lexicographically

This module also supports the standard fsdb options:

-d: Enable debugging output.
-i or --input InputSource: Read from InputSource, typically a file name, or - for standard input, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.
-o or --output OutputDestination: Write to OutputDestination, typically a file name, or - for standard output, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.
--autorun or --noautorun: By default, programs process automatically, but Fsdb::Filter objects in Perl do not run until you invoke the run() method. The --(no)autorun option controls that behavior within Perl.
--help: Show help.
--man: Show full manual.

Sample Usage

Input

    #fsdb name id test1
    a 1 80
    b 2 70
    c 3 65
    d 4 90
    e 5 70
    f 6 90

Command

    cat DATA/grades.fsdb | dbcolpercentile test1

Output

        #fsdb name id test1 percentile
        d       4       90      1
        f       6       90      1
        a       1       80      0.66667
        b       2       70      0.5
        e       5       70      0.5
        c       3       65      0.16667
        #  | dbsort -n test1
        #   | dbcolpercentile test1

Command 2

    cat DATA/grades.fsdb | dbcolpercentile --rank test1

Output 2

        #fsdb name id test1 rank
        d       4       90      1
        f       6       90      1
        a       1       80      3
        b       2       70      4
        e       5       70      4
        c       3       65      6
        #  | dbsort -n test1
        #   | dbcolpercentile --rank test1

AUTHOR and COPYRIGHT

This program is distributed under terms of the GNU general public license, version 2. See the file COPYING with the distribution for details.

Referenced By

dbcolstats(1), dbcolstatscores(1).

2021-01-27 perl v5.32.1 User Contributed Perl Documentation