git.slaskete.net - einar-bin/blob - randomness.sh

   1 #!/bin/bash
   2 # Visualize how random the $RANDOM function is
   3 # while demonstrating some neat array functions and things
   4
   5 # Check for sane parameter
   6 if [[ "${1}" -lt 50 ]]; then
   7     echo "Please input integer higher than 50"
   8     exit 1
   9 fi
  10
  11 # Declare arrays
  12 declare -A Count=()
  13 declare -A Graph=()
  14
  15 # Loop n times
  16 for ((n=0;n<${1};n++)); do
  17     # Assign random number, use modulo to reduce to desired range, add 1 to get rid of 0
  18     Rand=$(( ( RANDOM % 8 )  + 1 ))
  19     # Our Count array needs to be increased
  20     (( Count[${Rand}]++ ))
  21     # And append a character to our graph
  22     Graph[$Rand]+=█
  23 done
  24
  25 # Find extremes
  26 Max=${Count[1]}
  27 for n in "${Count[@]}"; do
  28     (( n > Max )) && Max=${n}
  29 done
  30
  31 Min=${Count[1]}
  32 for n in "${Count[@]}"; do
  33     (( n < Min )) && Min=${n}
  34 done
  35
  36 # Find mean
  37 Mean=$(bc <<< "scale=2;${1}/${#Count[@]}")
  38
  39 # Unset Graph array if we can't get it to fit on screen
  40 MaxWidth=$(tput cols)
  41 (( MaxWidth -= 10 ))
  42
  43 if [[ "${Max}" -gt "${MaxWidth}" ]]; then
  44     unset Graph
  45 fi
  46
  47 # Loop through the Count array, note the # which returns the size of the array for us
  48 for ((n=1;n<=${#Count[@]};n++)); do
  49     # printf to get some better formatting (space padding)
  50     printf "%-3s %-5s %s\n" ${n} ${Count[$n]} ${Graph[$n]}
  51 done
  52 echo -e "\nMin: ${Min}, Max: ${Max}, Mean: ${Mean}"