simple statistics from the command line interface (CLI)
Imagine you have this sample file:
$ cat numbers.txt
1
2
3
4
5
6
7
8
9
10
How do you calculate the sum of the numbers?
If you ask around, you'll come up with suggestions like these:
$ awk '{s+=$1} END {print s}' numbers.txt
55
$ perl -lne '$x += $_; END { print $x; }' numbers.txt
55
$ sum=0; while read num ; do sum=$(($sum + $num)); done < numbers.txt ; echo $sum
55
$ paste -sd+ numbers.txt | bc
55
Now imagine that you need to calculate the arithmetic mean, median, or standard deviation...
"st" is a command-line tool to calculate simple statistics from a file or standard input.
Let's start with "sum":
$ st --sum numbers.txt
55
That was easy!
How about mean and standard deviation?
$ st --mean --stddev numbers.txt
mean stddev
5.5 3.02765
If you don't specify any options, you'll get this output:
$ st numbers.txt
N min max sum mean stddev
10 1 10 55 5.5 3.02765
You can switch rows and columns using the "--transpose-output" option:
$ st --transpose-output numbers.txt
N 10
min 1
max 10
sum 55
mean 5.5
stddev 3.02765
The "--summary" option will provide the five-number summary:
$ st --summary numbers.txt
min q1 median q3 max
1 3.5 5.5 7.5 10
And "--complete" will print a complete description:
$ st --complete numbers.txt
N min q1 median q3 max sum mean stddev stderr
10 1 3.5 5.5 7.5 10 55 5.5 3.02765 0.957427
"R" and Octave are integrated suites for data manipulation, calculation and graphical display.
They provide high-level interpreted languages, capabilities for the numerical solution of linear and nonlinear problems, and for performing other numerical experiments, including statistical tests, classification, clustering, etc.
"st" is a simpler solution for simpler problems, focused on descriptive statistics for small datasets, handy when you need quick results without leaving the shell.
st [options] [file]
--N|n|count
--mean|avg|m
--stddev|sd
--stderr|sem|se
--sum|s
--var|variance
--min
--q1
--median
--q3
--max
--percentile=<0..1>
--quartile=<1..4>
If no functions are selected, "st" will print the default output:
N min max sum mean stddev
You can also use the following predefined sets of functions:
--summary # five-number summary (min q1 median q3 max)
--complete # everything
--format|fmt|f=<value> # default: "%g"
--delimiter|d=<value> # default: "\t"
--no-header|nh # don't display header
--transpose-output|to # switch rows and columns
Examples of valid formats ("--format" option):
%d signed integer, in decimal
%e floating-point number, in scientific notation
%f floating-point number, in fixed decimal notation
%g floating-point number, in %e or %f notation
By default, "st" skips invalid input with a warning.
You can change this behavior with the following options:
--strict # throws an error, interrupting process
--quiet|q # no warning
Nelson Ferraz <[email protected]>
Send comments, suggestions and bug reports to:
https://github.com/nferraz/st/issues
Or fork the code on github: