Data commit

Task/Angle-difference-between-two-bearings/Python/angle-difference-between-two-bearings-1.py

@@ -0,0 +1,28 @@
+from __future__ import print_function
+
+def getDifference(b1, b2):
+	r = (b2 - b1) % 360.0
+	# Python modulus has same sign as divisor, which is positive here,
+	# so no need to consider negative case
+	if r >= 180.0:
+		r -= 360.0
+	return r
+
+if __name__ == "__main__":
+	print ("Input in -180 to +180 range")
+	print (getDifference(20.0, 45.0))
+	print (getDifference(-45.0, 45.0))
+	print (getDifference(-85.0, 90.0))
+	print (getDifference(-95.0, 90.0))
+	print (getDifference(-45.0, 125.0))
+	print (getDifference(-45.0, 145.0))
+	print (getDifference(-45.0, 125.0))
+	print (getDifference(-45.0, 145.0))
+	print (getDifference(29.4803, -88.6381))
+	print (getDifference(-78.3251, -159.036))
+
+	print ("Input in wider range")
+	print (getDifference(-70099.74233810938, 29840.67437876723))
+	print (getDifference(-165313.6666297357, 33693.9894517456))
+	print (getDifference(1174.8380510598456, -154146.66490124757))
+	print (getDifference(60175.77306795546, 42213.07192354373))

Task/Angle-difference-between-two-bearings/Python/angle-difference-between-two-bearings-2.py

@@ -0,0 +1,89 @@
+'''Difference between two bearings'''
+
+from math import (acos, cos, pi, sin)
+
+
+# bearingDelta :: Radians -> Radians -> Radians
+def bearingDelta(ar):
+    '''Difference between two bearings,
+       expressed in radians.'''
+    def go(br):
+        [(ax, ay), (bx, by)] = [
+            (sin(x), cos(x)) for x in [ar, br]
+        ]
+        # cross-product > 0 ?
+        sign = +1 if 0 < ((ay * bx) - (by * ax)) else -1
+        # sign * dot-product
+        return sign * acos((ax * bx) + (ay * by))
+    return lambda br: go(br)
+
+
+# TEST ----------------------------------------------------
+# main :: IO ()
+def main():
+    '''Test and display'''
+
+    # showMap :: Degrees -> Degrees -> String
+    def showMap(da, db):
+        return unwords(
+            str(x).rjust(n) for n, x in
+            [
+                (22, str(da) + ' +'),
+                (24, str(db) + '  -> '),
+                (7, round(
+                    degrees(
+                        bearingDelta
+                        (radians(da))
+                        (radians(db))
+                    ), 2)
+                 )
+            ]
+        )
+
+    print(__doc__ + ':')
+    print(
+        unlines(showMap(a, b) for a, b in [
+            (20, 45),
+            (-45, 45),
+            (-85, 90),
+            (-95, 90),
+            (-45, 125),
+            (-45, 145),
+            (-70099.74233810938, 29840.67437876723),
+            (-165313.6666297357, 33693.9894517456),
+            (1174.8380510598456, -154146.66490124757),
+            (60175.77306795546, 42213.07192354373)
+        ]))
+
+
+# GENERIC ----------------------------------------------
+
+
+# radians :: Float x => Degrees x -> Radians x
+def radians(x):
+    '''Radians derived from degrees.'''
+    return pi * x / 180
+
+
+# degrees :: Float x => Radians x -> Degrees x
+def degrees(x):
+    '''Degrees derived from radians.'''
+    return 180 * x / pi
+
+
+# unlines :: [String] -> String
+def unlines(xs):
+    '''A single newline-delimited string derived
+       from a list of strings.'''
+    return '\n'.join(xs)
+
+
+# unwords :: [String] -> String
+def unwords(xs):
+    '''A space-separated string derived from
+       a list of words.'''
+    return ' '.join(xs)
+
+
+if __name__ == '__main__':
+    main()

Task/Angle-difference-between-two-bearings/Python/angle-difference-between-two-bearings-3.py

@@ -0,0 +1,17 @@
+"""
+Difference between two bearings
+"""
+
+def  delta_bearing(b1 , b2):
+	return ((b2-b1+540)%360)-180
+
+dataSet = [[20, 45], [-45, 45], [-85, 90], [-95, 90], [-45, 125], [-45, 145], \
+	[29.4803, -88.6381], [-78.3251, -159.036], \
+	[-70099.74233810938, 29840.67437876723], \
+	[-165313.6666297357, 33693.9894517456], \
+	[1174.8380510598456, -154146.66490124757], \
+	[60175.77306795546, 42213.07192354373]]
+
+print('.{:-^19}.{:-^19}.{:-^9}.' .format(" b1 ", " b2 ", " Δ b " ))
+for Δ in dataSet:
+	print('|{: > 19}|{: > 19}|{: > 9.4f}|' .format(Δ[0], Δ[1],delta_bearing(Δ[0],Δ[1])))