Hi Wes,
It's me again with problems with the angles of roadways. I have found the tool you provided, which is pretty awesome, has the tendency to produce a point on angles that are greater than the parameters set in the model. Although the tool does find these angles at intersections, it tends to produce some outside the parameters set. These extra points that are suppose to signify angles within the tool parameters are always located where buffers overlap. What do you think? Can these be removed somehow via your tool?
Thanks!
This post has been on my mind for a while, and here's what I came up with. I suspect it's quite similar to Wes' previously posted solution, but works for all license levels:
>>> import os
... fc = "myLines"
... sr = arcpy.Describe(fc).spatialReference
... radius = 50
... out_fc = r'in_memory\points'
... int_pt = r'in_memory\int_pt'
... arcpy.Intersect_analysis(fc,int_pt,output_type='POINT')
... diss_int_pt = r'in_memory\diss_int_pt'
... arcpy.Dissolve_management(int_pt,diss_int_pt,'#',[["FID","MIN"]],"SINGLE_PART")
... buff = r'in_memory\buff'
... arcpy.Buffer_analysis(diss_int_pt,buff,str(radius) + ' METERS')
... buff_line_int = r'in_memory\buff_line_int'
... arcpy.Intersect_analysis([buff,fc],buff_line_int,output_type='POINT')
... sing_buff_line_int = r'in_memory\sing_buff_line_int'
... arcpy.MultipartToSinglepart_management(buff_line_int,sing_buff_line_int)
... new_points = {}
... with arcpy.da.SearchCursor(diss_int_pt,['OID@','SHAPE@'],spatial_reference=sr) as cursor1:
... for row1 in cursor1:
... cent_pt = row1[1].centroid
... angs = []
... with arcpy.da.SearchCursor(sing_buff_line_int,'SHAPE@','\"FID_buff\" = ' + str(row1[0]),spatial_reference=sr) as cursor2:
... for row2 in cursor2:
... buff_pt = row2[0].centroid
... dx = cent_pt.X - buff_pt.X
... dy = cent_pt.Y - buff_pt.Y
... if dx < 0 and dy <= 0:
... ang = math.degrees(math.atan(abs(dy/dx)))
... if dx <= 0 and dy > 0:
... ang = math.degrees(math.atan(abs(dx/dy))) + 270
... if dx > 0 and dy >= 0:
... ang = math.degrees(math.atan(abs(dy/dx))) + 180
... if dx >= 0 and dy < 0:
... ang = math.degrees(math.atan(abs(dx/dy))) + 90
... angs.append(ang)
... angs.sort()
... for i in range(1,len(angs)):
... mid_ang = ((angs + angs[i-1])/2)
... ang_diff = angs - angs[i-1]
... new_x = cent_pt.X + (radius * math.cos(math.radians(mid_ang)))
... new_y = cent_pt.Y + (radius * math.sin(math.radians(mid_ang)))
... new_point = arcpy.PointGeometry(arcpy.Point(new_x, new_y),sr)
... new_points[str(row1[0]) + '_' + str(i)] = [ang_diff,new_point]
... mid_ang = (((360-angs[-1]) + angs[0])/2) - (360-angs[-1])
... ang_diff = (360-angs[-1]) + angs[0]
... new_x = cent_pt.X + (radius * math.cos(math.radians(mid_ang)))
... new_y = cent_pt.Y + (radius * math.sin(math.radians(mid_ang)))
... new_point = arcpy.PointGeometry(arcpy.Point(new_x, new_y),sr)
... new_points[str(row1[0]) + '_0'] = [ang_diff,new_point]
... arcpy.CreateFeatureclass_management(os.path.dirname(out_fc),os.path.basename(out_fc),'POINT',spatial_reference=sr)
... arcpy.AddField_management(out_fc,'FID_buff',"LONG")
... arcpy.AddField_management(out_fc,'ANGLE',"DOUBLE")
... iCursor = arcpy.da.InsertCursor(out_fc,['SHAPE@','FID_buff','ANGLE'])
... for k,v in new_points.iteritems():
... row = [v[1],k.split('_')[0],v[0]]
... iCursor.insertRow(row)
The script makes points on each buffer in isolation, so there is no influence from any other buffer. I agree that the buffer size should be as low as reasonable. You would run into problems if the buffer overlapped other intersections or parallel streets.
Good:
Bad:
