xref: /freebsd/usr.bin/ministat/README (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1$FreeBSD$
2
3A small tool to do the statistics legwork on benchmarks etc.
4
5Prepare your data into two files, one number per line
6run
7	./ministat data_before data_after
8
9and see what it says.
10
11You need at least three data points in each data set, but the more
12you have the better your result generally gets.
13
14Here are two typical outputs:
15
16x _1
17+ _2
18+--------------------------------------------------------------------------+
19|x            +    x+      x            x   x             +           ++   |
20|        |_________|______AM_______________|__A___________M_______________||
21+--------------------------------------------------------------------------+
22    N           Min           Max        Median           Avg        Stddev
23x   5         36060         36138         36107       36105.6     31.165686
24+   5         36084         36187         36163       36142.6     49.952978
25No difference proven at 95.0% confidence
26
27Here nothing can be concluded from the numbers.  It _may_ be possible to
28prove something if many more measurements are made, but with only five
29measurements, nothing is proven.
30
31
32x _1
33+ _2
34+--------------------------------------------------------------------------+
35|                                                               +          |
36|                               x                               +         +|
37|x                    x         x          x                    +         +|
38|         |_______________A_____M_________|                   |_M___A____| |
39+--------------------------------------------------------------------------+
40    N           Min           Max        Median           Avg        Stddev
41x   5         0.133         0.137         0.136        0.1354  0.0015165751
42+   5         0.139          0.14         0.139        0.1394 0.00054772256
43Difference at 95.0% confidence
44        0.004 +/- 0.00166288
45        2.95421% +/- 1.22812%
46        (Student's t, pooled s = 0.00114018)
47
48Here we have a clearcut difference, not very big, but clear and unambiguous.
49
50
51