An Experiment in Randomness



You can print a random number between 1-10 with the following command.

echo $((( RANDOM % 10 )+1))

Creating random numbers

If you change it so the output is between 0-9 you get decently even results.

cat /dev/null > random.txt && cat /dev/null > random2.txt && for ((i=0; i<=9999;i++)); do echo $((( RANDOM % 10 ))) >> random.txt ; done && for ((i=0; i<=9;i++)); do echo $(grep -c $i random.txt) $i; done  |  sort -n

Note that you can change the command to be between 1-10, but all the 1’s in 10 will get grepped and counted as 1’s.

The above command should return something similar to the following. Sorted by lowest occurrences first.

943 5
945 8
985 7
996 2
997 6
1005 3
1012 9
1016 4
1033 0
1068 1
admin@localhost:~$

We can plot them in LibreOffice Calc.

Plot with GnuPlot

Gnuplot is another utility that you can use to plot numbers. Example is below.

cat /dev/null > random.txt && cat /dev/null > random2.txt && for ((i=0; i<=9999;i++)); do echo $((( RANDOM % 10 ))) >> random.txt ; done && for ((i=0; i<=9;i++)); do echo $i $(grep -c $i random.txt) ; done  |  sort -n | gnuplot -p -e 'plot "/dev/stdin"'

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