dbrowdiff - compute row-by-row differences of some column


dbrowdiff [-B|-I] column


For a given column, compute the differences between each row of the table. Differences are output to two new columns, "absdiff" and "pctdiff".

Differences are either relative to the previous column (incremental mode), or relative to the first row (baseline mode), the default.


-B or --baseline
Select baseline mode (the default), where differences are relative to the first row.
-I or --incremental
Select incremental mode, where differences are relative to the previous row.
-f FORMAT or --format FORMAT
Specify a printf(3)-style format for output statistics. Defaults to "%.5g".

This module also supports the standard fsdb options:

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.
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    #fsdb      event   clock
    _null_getpage+128       815812813.281756
    _null_getpage+128       815812813.328709
    _null_getpage+128       815812813.353830
    _null_getpage+128       815812813.357169
    _null_getpage+128       815812813.375844
    _null_getpage+128       815812813.378358
    #  | /home/johnh/BIN/DB/dbrow 
    #  | /home/johnh/BIN/DB/dbcol event clock


    cat DATA/kitrace.fsdb | dbrowdiff clock


    #fsdb      event   clock   absdiff pctdiff
    _null_getpage+128       815812813.281756        0       0
    _null_getpage+128       815812813.328709        0.046953        5.7554e-09
    _null_getpage+128       815812813.353830        0.072074        8.8346e-09
    _null_getpage+128       815812813.357169        0.075413        9.2439e-09
    _null_getpage+128       815812813.375844        0.094088        1.1533e-08
    _null_getpage+128       815812813.378358        0.096602        1.1841e-08
    #  | /home/johnh/BIN/DB/dbrow 
    #  | /home/johnh/BIN/DB/dbcol event clock
    #  | dbrowdiff clock


Fsdb. dbcolmovingstats. dbrowuniq. dbfilediff.

dbrowdiff, dbrowuniq, and dbfilediff are similar but different. dbrowdiff computes row-by-row differences for a column, dbrowuniq eliminates rows that have no differences, and dbfilediff compares fields of two files.


Copyright (C) 1991-2008 by John Heidemann <johnh [at]>

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