freebsd-dev/usr.bin/ministat
Kristof Provost 09a3b0db35 Clarify the ministat default width
The man page states that:
'-w width    Width of ASCII-art plot in characters, default is 74.'

This is not entirely correct. The mini-help is more accurate:
'-w : width of graph/test output (default 74 or terminal width)'

In other words: the man page fails to explain that ministat will default
to the terminal width, not 74. It will only fall back to 74 if stdout is
not a TTY.

Submitted by:	Ben Hutchings <ben@decadent.org.uk>
Approved by:	philip (mentor)
2015-03-26 17:13:11 +00:00
..
chameleon A small statistics tool for gauging the statistical significance 2003-08-13 07:21:54 +00:00
iguana
Makefile Convert to usr.bin/ to LIBADD 2014-11-25 14:29:10 +00:00
ministat.1 Clarify the ministat default width 2015-03-26 17:13:11 +00:00
ministat.c ministat(1): replace malloc + memset with calloc. 2015-02-17 23:20:19 +00:00
README

$FreeBSD$

A small tool to do the statistics legwork on benchmarks etc.

Prepare your data into two files, one number per line
run 
	./ministat data_before data_after

and see what it says.

You need at least three data points in each data set, but the more
you have the better your result generally gets.

Here are two typical outputs:

x _1
+ _2
+--------------------------------------------------------------------------+
|x            +    x+      x            x   x             +           ++   |
|        |_________|______AM_______________|__A___________M_______________||
+--------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x   5         36060         36138         36107       36105.6     31.165686
+   5         36084         36187         36163       36142.6     49.952978
No difference proven at 95.0% confidence

Here nothing can be concluded from the numbers.  It _may_ be possible to
prove something if many more measurements are made, but with only five
measurements, nothing is proven.


x _1
+ _2
+--------------------------------------------------------------------------+
|                                                               +          |
|                               x                               +         +|
|x                    x         x          x                    +         +|
|         |_______________A_____M_________|                   |_M___A____| |
+--------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x   5         0.133         0.137         0.136        0.1354  0.0015165751
+   5         0.139          0.14         0.139        0.1394 0.00054772256
Difference at 95.0% confidence
        0.004 +/- 0.00166288
        2.95421% +/- 1.22812%
        (Student's t, pooled s = 0.00114018)

Here we have a clearcut difference, not very big, but clear and unambiguous.