offsetting a point by 90 degrees

offset_pt.py

#offset the points to the appropriate side based on the direction of the arc and the 
#side that these addresses should be on.  this function uses trigonometry to move a 
#a delta x and and delta y.  
#then return new X and Y as a list
#arguments:
#-myX is the X value of the input point
#-myY is the Y value of the input point
#-mySide is the side of the line (left or right)
#-myAz is the azimuth direction of the line (0-360)
def offset_pt(myX, myY, mySide, myAz):
	#we are offsetting by 5 meters
	theOffset = 10
	#a perpendicular line on the left side is always -90 degrees from the original
	#direction of the line
	if mySide == "left":
		newDir = myAz - 90
	#a perpendicular line on the right side is always +90 degrees from the original
	#direction of the line
	if mySide == "right":
		newDir = myAz + 90
	#do do some basic trig to get the delta X and the delta y of the new point.
	#assuming the new perpendicular line is the hypotenuse, then the new point is 
	#delta X is the distance along the X access or the adjacent line in a right triangle
	#here, we have to use the math.radians to convert the new direction to and then 
	#pass that to the sin method; similarly, delta Y is the the opposite line in a right
	#triangle, so we use cosine of that angle to acquire this distance.
	newX = myX + (math.sin(math.radians(newDir)))*theOffset
	newY = myY + (math.cos(math.radians(newDir)))*theOffset
	return ([newX, newY])