Hi Abdel,I suppose the speed would not matter as long as the line from point Q extent outside the convex hull polygon. So with that in mind, take a look at the Python code below. It works with a list of points (hard coded in this snippet) and an angle (could be arithmetic or geographic). The following steps are carried out:
- the points are added to a multipoint object
- the convex hull polygon is calculated from the multipoint
- the boundary is extracted from the polygon
- the centroid of the polygon is in this case used for point Q
- to be sure that the line starting in point Q will exit the polygon, I use a "large" length (so no speed used)
- the point Q2 is determined using the length and angle
- a line is created using Q and Q2
- the line is intersected with the boundary to obtain the desired intersection point
- the X and Y of the resulting point is printed
def main():
import arcpy, os
# input points
pnts = [[200,800],[100, 500],[300,100],[1000,200],[1200,700]]
# input angle
angle_geo = 100 # geographic degrees
angle_ari = arithmatic_geographic(angle_geo) # = 350 in arithmetic degrees
# create a multi point from input points
arr_mp = arcpy.Array()
for p in pnts:
pnt = arcpy.Point(p[0], p[1])
arr_mp.add(pnt)
mp = arcpy.Multipoint(arr_mp)
# determine convex hull of input points
pol = mp.convexHull()
# get boundary of convex hull polygon
bnd = pol.boundary()
# let's take centroid for Q
q = pol.centroid
# determine line length (enough to intersect boundary)
length = pol.extent.width + pol.extent.height
# create second point (Q2)
dx, dy = LengthDir(length, angle_ari)
q2 = arcpy.Point(q.X + dx, q.Y + dy)
# make line of Q and Q2
arr_line = arcpy.Array()
arr_line.add(q)
arr_line.add(q2)
line = arcpy.Polyline(arr_line)
# intersect (other, dimension), dimension can be 1 or 2
pnt_int = line.intersect(bnd, 1) # returns mp
# print resulting intersection coordinates
for p in pnt_int:
print p.X, p.Y
def arithmatic_geographic(angle):
new_angle = angle + 270
while new_angle > 360:
new_angle -= 360
return 360 - new_angle
def LengthDir(length, angle):
import math
radian_angle = angle * math.pi / 180
return length * math.cos(radian_angle), length * math.sin(radian_angle)
if __name__ == '__main__':
main()
If you can explain what your input data looks like, the code can be adapted.Kind regards,Xander
