NAME

     ministat — statistics utility

SYNOPSIS

     ministat [-Ans] [-C column] [-c confidence_level] [-d delimiter] [-w [width]] [file ...]

DESCRIPTION

     The ministat command calculates fundamental statistical properties of numeric data in the specified files
     or, if no file is specified, standard input.

     The options are as follows:

     -A          Just report the statistics of the input and relative comparisons, suppress the ASCII-art plot.

     -n          Just report the raw statistics of the input, suppress the ASCII-art plot and the relative
                 comparisons.

     -s          Print the average/median/stddev bars on separate lines in the ASCII-art plot, to avoid overlap.

     -C column   Specify which column of data to use.  By default the first column in the input file(s) are
                 used.

     -c confidence_level
                 Specify desired confidence level for Student's T analysis.  Possible values are 80, 90, 95, 98,
                 99 and 99.5 %

     -d delimiter
                 Specifies the column delimiter characters, default is SPACE and TAB.  See strtok(3) for
                 details.

     -w width    Width of ASCII-art plot in characters.  The default is the terminal width, or 74 if standard
                 output is not a terminal.

     A sample output could look like this:

             $ ministat -s -w 60 iguana chameleon
             x iguana
             + chameleon
             +------------------------------------------------------------+
             |x      *  x            *      +              + x           +|
             | |________M______A_______________|                          |
             |             |________________M__A___________________|      |
             +------------------------------------------------------------+
                 N        Min        Max     Median        Avg       Stddev
             x   7         50        750        200        300    238.04761
             +   5        150        930        500        540    299.08193
             No difference proven at 95.0% confidence

     If ministat tells you, as in the example above, that there is no difference proven at 95% confidence, the
     two data sets you gave it are for all statistical purposes identical.

     You have the option of lowering your standards by specifying a lower confidence level:

             $ ministat -s -w 60 -c 80 iguana chameleon
             x iguana
             + chameleon
             +------------------------------------------------------------+
             |x      *  x            *      +              + x           +|
             | |________M______A_______________|                          |
             |             |________________M__A___________________|      |
             +------------------------------------------------------------+
                 N        Min        Max     Median        Avg       Stddev
             x   7         50        750        200        300    238.04761
             +   5        150        930        500        540    299.08193
             Difference at 80.0% confidence
                   240 +/- 212.215
                   80% +/- 70.7384%
                   (Student's t, pooled s = 264.159)

     But a lower standard does not make your data any better, and the example is only included here to show the
     format of the output when a statistical difference is proven according to Student's T method.

SEE ALSO

     Any mathematics text on basic statistics, for instances Larry Gonicks excellent "Cartoon Guide to
     Statistics" which supplied the above example.

HISTORY

     The ministat command was written by Poul-Henning Kamp out of frustration over all the bogus benchmark
     claims made by people with no understanding of the importance of uncertainty and statistics.

     From FreeBSD 5.2 it has lived in the source tree as a developer tool, graduating to the installed system
     from FreeBSD 8.0.