Compute angles between intersecting roads
Thanks Hornbydd My code is as follows:
>>> import arcpy
... import os
... fc = "DubaiRoads_Extent"
... sr = arcpy.Describe(fc).spatialReference
... radius = 3
... out_fc = r'J:\research\MapLiteracyStudy\Dubai.gdb\points'
... int_pt = r'J:\research\MapLiteracyStudy\Dubai.gdb\int_pt'
... arcpy.Intersect_analysis(fc,int_pt,output_type='POINT')
... diss_int_pt = r'J:\research\MapLiteracyStudy\Dubai.gdb\diss_int_pt'
... arcpy.Dissolve_management(int_pt,diss_int_pt,'#',[["OBJECTID","MIN"]],"SINGLE_PART")
... buff = r'J:\research\MapLiteracyStudy\Dubai.gdb\buff'
... arcpy.Buffer_analysis(diss_int_pt,buff,str(radius) + ' METERS')
... buff_line_int = r'J:\research\MapLiteracyStudy\Dubai.gdb\buff_line_int'
... arcpy.Intersect_analysis([buff,fc],buff_line_int,output_type='POINT')
... sing_buff_line_int = r'J:\research\MapLiteracyStudy\Dubai.gdb\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[i] + angs[i-1])/2)
... ang_diff = angs[i] - 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 runs, with the resulting image:
And the buffers look like:
However, in the example provided by Darren Wiens, it the result should be:
I can't figure out why all of my calculated points seem to be in a circle around my study area, as opposed to on the buffers between the intersecting lines.
Any help would be greatly appreciated.
Erin
Actually Duncan... it is a Discussion rather than a question (could be a bloop)... so droning ad nauseum is permissible 
Good point but I do find the distinction between the two blurred as visually the posting types look almost identical unless you pick up that tiny blue icon (which hands up I did not notice!). Just trying to encourage people who post to format their code as that is such a trivial thing to do but can make such a visual impact, especially with python.
Now I'm just going off to sharpen my pointy stick ready for some more droning on! 
