File: props.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright © 2024 pacman64
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining a copy
   8 # of this software and associated documentation files (the “Software”), to deal
   9 # in the Software without restriction, including without limitation the rights
  10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 # copies of the Software, and to permit persons to whom the Software is
  12 # furnished to do so, subject to the following conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be included in
  15 # all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23 # SOFTWARE.
  24 
  25 
  26 # props [x] [y...]
  27 #
  28 # Show various PROPortionS involving 2 numbers; when given only 1 number,
  29 # show its inverse.
  30 
  31 
  32 # handle help options
  33 case "$1" in
  34     -h|--h|-help|--help)
  35         awk '/^# +props/, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  36         exit 0
  37     ;;
  38 esac
  39 
  40 awk '
  41 BEGIN {
  42     if (ARGC < 2 || ARGV[1] + 0 == 0) {
  43         print "props [x] [y...]";
  44         print "";
  45         print "Show various PROPortionS involving 2 numbers;"
  46         print "when given only 1 number, show its inverse.";
  47         exit(1);
  48     }
  49 
  50     # handle the 1-number case
  51     if (ARGC == 2) {
  52         x = ARGV[1] + 0.0;
  53         printf("x       =  %f\n", x);
  54         printf("1 / x  ~=  %f\n", div(1, x));
  55         exit(0);
  56     }
  57 
  58     # get values and sort them
  59     x = ARGV[1] + 0.0; # min
  60     y = ARGV[2] + 0.0; # max
  61     delete ARGV[1];
  62     delete ARGV[2];
  63     if (x > y) {
  64         temp = x;
  65         x = y;
  66         y = temp;
  67     }
  68 
  69     printf("min: x = %f\n", x);
  70     printf("max: y = %f\n", y);
  71     # printf("sum:     %f\n", x + y);
  72     # printf("diff:    %f\n", y - x);
  73     # printf("avg:     %f\n", (x + y) / 2);
  74     print;
  75     printf("     x / y   ~=  %f\n", div(x, y));
  76     printf("1 - (x / y)  ~=  %f\n", div(y - x, y));
  77     printf("     y / x   ~=  %f\n", div(y, x));
  78     print;
  79     printf("x / (x + y)  ~=  %f\n", div(x, x + y));
  80     printf("y / (x + y)  ~=  %f\n", div(y, x + y));
  81     print;
  82     printf("x / (y - x)  ~=  %f\n", div(x, y - x));
  83     printf("y / (y - x)  ~=  %f\n", div(y, y - x));
  84     # printf("(y - x) / y  ~=  %f\n", div(y - x, y));
  85 }
  86 
  87 function div(a, b) {
  88     if (b != 0) {
  89         return a / b;
  90     }
  91     return (a >= 0 ? "+inf" : "-inf") + 0;
  92 }
  93 ' "$@"