Hey Everyone,
Currently what I am trying to do is rotate polylines in certain grid sections to the same orientation of existing polylines in that grid. This seems to be quite complicated as I have looked quite extensively for something like this, but to no success. Currently right now I have implemented a tool that was posted here arcpy - Drawing parallel lines inside polygons (Well Paths) using ArcGIS Desktop? - Geographic Infor... now this works for me and does what it should... but here is my problem posted below.
The grid lines that were drawn automatically (yellow) are horizontal where as I would like them be vertical. If there is a way through arcpy or other tools where I can rotate these lines to be the same direction of polylines that are currently there. This is just one example, this happens many times in different areas.
Thank you!
Hey Dan, These links and suggestions were super helpful! Ive been able to at least rotate them now and this is the fartheset I have been yet! The only problem I am facing currently is those starting points. For example, If my lines are going vertical but I want them to be horizontal, I need to change that starting point to a different line or else it looks like this.
Now I believe I have the correct logic on how to fix this problem, but how to put into code is another story haha. I will use a search cursor on the grid shapefile to search for the azimuth angle lines in that grid should be drawn at. I will give ranges after in a If statement saying If row[0] = 90 (for example), I will plot my starting points on the West or East side of the polygon cause then I know they will be drawn horizontally.
Where I am stuck is distinguishing which side is west, east, north, south on each feature I iterate through, and then assigning that as my line where I plot the first starting points. After that I can do the add geometry, bearing distance and I think I will have solved my problem.
Here's some code that I have been experimenting with that may give you some ideas. It takes a polygon feature class and creates a layer of points marking each polygon's centroid. It also creates a line through the centroid at a given azimuth.
From here, you need to add additional parallel lines and clip them to the polygon.
import arcpy
import math
def draw_line(point, distance, bearing):
angle = 90 - bearing
bearing = math.radians(bearing)
angle = math.radians(angle)
cosa = math.cos(angle)
cosb = math.cos(bearing)
x1, y1 = \
(point[0] + (distance * cosa), point[1] + (distance * cosb))
x2, y2 = \
(point[0] - (distance * cosa), point[1] - (distance * cosb))
return [[x1, y1], [x2, y2]]
polyFC = "poly_line" # the polygon feature layer
azimuth = 347
desc = arcpy.Describe(polyFC)
SR = desc.spatialReference
arcpy.env.overwriteOutput = True
arcpy.env.outputCoordinateSystem = SR
points = []
lines = []
with arcpy.da.SearchCursor(polyFC,['SHAPE@']) as cursor:
for row in cursor:
centroid = row[0].centroid
points.append(arcpy.PointGeometry(centroid))
dist = 0
for part in row[0]:
for pnt in part:
cent_vert_dist = arcpy.PointGeometry(pnt).distanceTo(centroid)
if cent_vert_dist > dist:
dist = cent_vert_dist
# far_point = arcpy.PointGeometry(pnt)
# points.append(far_point)
feature_info = [ draw_line((centroid.X, centroid.Y), dist, azimuth) ]
for feature in feature_info:
lines.append(
arcpy.Polyline(
arcpy.Array([arcpy.Point(*coords) for coords in feature])))
arcpy.CopyFeatures_management(points,'in_memory\points')
arcpy.CopyFeatures_management(lines,'in_memory\lines')Randy this helps a lot, awesome script! I am tweaking it just a bit where instead of one singular azimuth to go off of, I would like to pull my azimuth value from a field within the polygon shapefile. I have been attempting to use a search cursor to look on that field and then say row=azimuth, but have not been successful! What I get is this...
Here is the portion of code I tweaked;
Perhaps my syntax is a bit wonky somewhere. Thank you again for everything
Also This is what I am trying to pull as my azimuth value
each shape it iterates through should draw lines based on this value.
Hey Dan, wow this awesome!! Pretty sure exactly the last step I need, but I am struggling a bit with integrating it into my current script. So currently I am iterating through each grid shape, finding the center point and drawing a line based on a azimuth that is given to me. That is all good, now I would like to take that current line and replicate it X number of times and a X distance from it.
I see that your scipt indeed does this! I am not sure If I understand all the logic and code that is happening, there is a lot going on and I am not sure If I am to use all of it or only pieces. Given that I have already created a line, can I Incorporate some portions of your script where I am still iterating through each grid creating a line and replicating it. So it shows something like this (replicates created manually)
I am essentially trying to keep it all within one loop and trying to incorporate your code in this area of mine;
Thank you again for all the help, I am still looking at your code and trying to understand how I can implement it into mine. I am using the script Randy provided above with just a slight modification where I am grabbing the azimuth attribute from the table of the grid shapefile.
