ministat1

Usage

Overview

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.

-C column

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

-c confidence

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

-d delimiters

Specify the column delimiter characters, default is ‘ \t’ (i.e., a space and a tab). See strtok(3) for details.

-n

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

-q

Suppress printing of summary statistics and data-set names; typically for use alongside -n.

Not on Linux.

-s

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

-w width

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

ministat accepts up to seven input files.

Each dataset must contain at least three values.

Exit status

The ministat utility exits 0 on success, and >0 if an error occurs.

Examples

Let's consider two input files. The first one will be “iguana”:

50
200
150
400
750
400
150

The second one will be “chameleon”:

150
400
720
500
930

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 datasets 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% +/- 102.3%
      (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.