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MINISTAT(1) BSD General Commands Manual MINISTAT(1) 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, stan- dard 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, default is 74. 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 sta- tistical 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 exam- ple. HISTORY
The ministat command was written by Poul-Henning Kamp out of frustration over all the bogus benchmark claims made by people with no under- standing 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. BSD
November 10, 2012 BSD
