langs a-z

Task/Box-the-compass/UNIX-Shell/box-the-compass.sh

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+# List of abbreviated compass point labels
+compass_points=( N NbE N-NE NEbN NE NEbE E-NE EbN
+                 E EbS E-SE SEbE SE SEbS S-SE SbE
+                 S SbW S-SW SWbS SW SWbW W-SW WbS
+                 W WbN W-NW NWbW NW NWbN N-NW NbW )
+
+# List of angles to test
+test_angles=(  0.00  16.87  16.88  33.75  50.62  50.63  67.50
+              84.37  84.38 101.25 118.12 118.13 135.00 151.87
+             151.88 168.75 185.62 185.63 202.50 219.37 219.38
+             236.25 253.12 253.13 270.00 286.87 286.88 303.75
+             320.62 320.63 337.50 354.37 354.38 )
+
+
+# capitalize a string
+function capitalize {
+  echo "$1" | sed 's/^./\U&/'
+}
+
+# convert compass point abbreviation to full text of label
+function expand_point {
+  local label="$1"
+  set -- N north E east S south W west b " by "
+  while (( $# )); do
+    label="${label//$1/$2}"
+    shift 2
+  done
+  capitalize "$label"
+}
+
+# modulus function that returns 1..N instead of 0..N-1
+function amod {
+  echo $(( ($1 - 1) % $2 + 1 ))
+}
+
+# convert a compass angle from degrees into a box index (1..32)
+function compass_point {
+  #amod $(dc <<<"$1 5.625 + 11.25 / 1 + p") 32
+  amod $(bc <<<"($1 + 5.625) / 11.25 + 1") 32
+}
+
+#  Now output the table of test data
+header_format="%-7s | %-18s | %s\n"
+row_format="%7.2f | %-18s | %2d\n"
+printf "$header_format" "Degrees" "Closest Point" "Index"
+for angle in ${test_angles[@]}; do
+  let index=$(compass_point $angle)
+  abbr=${compass_points[index-1]}
+  label="$(expand_point $abbr)"
+  printf "$row_format" $angle "$label" $index
+done