Finding the shortest edge length of polygons

Question

I have 2,000+ polygons that I need to find the shortest perimeter edge for. Does anyone have any solutions? Thanks in advance!

StephenUsmar2 · Answer

Thanks everyone for your quick responses and great answers!

Solution is no longer needed (unfortunately), but for curiosity's sake, I was attempting to identify houses with long driveways (right of way access) by finding land parcel shapes with a short perimeter edge to represent a driveway edge. I couldn't find any other data source to indicate these so this is the best solution I could come up with.

XanderBakker · Answer

Hust did a little test to see if it would work and I get a result with this code (it will add fields to the input featureclass, so it's better to run this on a copy of your data): def main(): # will change the input fc (adding fields!) import arcpy fc = r'C:\GeoNet\ShortestEdge\data.gdb\polygons' generalize = 0.1 # change this value according to the tolerance in your data fc_out = r'C:\GeoNet\ShortestEdge\data.gdb\lines_v01' # output fields fld_len1 = "ShortestLength1" fld_from_pnt1 = "FromPoint1" fld_to_pnt1 = "ToPoint1" fld_len2 = "ShortestLength2" fld_from_pnt2 = "FromPoint2" fld_to_pnt2 = "ToPoint2" # add fields AddField(fc, fld_len1, "DOUBLE", None) AddField(fc, fld_from_pnt1, "TEXT", 100) AddField(fc, fld_to_pnt1, "TEXT", 100) AddField(fc, fld_len2, "DOUBLE", None) AddField(fc, fld_from_pnt2, "TEXT", 100) AddField(fc, fld_to_pnt2, "TEXT", 100) # update cursor feats = [] flds = ('SHAPE@', fld_len1, fld_from_pnt1, fld_to_pnt1, fld_len2, fld_from_pnt2, fld_to_pnt2) with arcpy.da.UpdateCursor(fc, flds) as curs: for row in curs: polygon = row[0] length1, from_pnt1, to_pnt1, line1 = GetShortestEdgeData(polygon) feats.append(line1) polygon2 = polygon.generalize(generalize) length2, from_pnt2, to_pnt2, line2 = GetShortestEdgeData(polygon2) feats.append(line2) curs.updateRow((polygon, length1, from_pnt1, to_pnt1, length2, from_pnt2, to_pnt2, )) # write lines to output fc for visual reference arcpy.CopyFeatures_management(feats, fc_out) def AddField(fc, fld_name, fld_type, fld_length): if len(arcpy.ListFields(fc, fld_name)) == 0: arcpy.AddField_management(fc, fld_name, fld_type, None, None, fld_length) def GetShortestEdgeData(polygon): min_length = 99999 prev_pnt = None side = None sr = polygon.spatialReference for part in polygon: for pnt in part: if prev_pnt is None: pass else: if pnt is None: pass else: length = GetDist(pnt, prev_pnt) if length < min_length: min_length = length line = arcpy.Polyline(arcpy.Array([prev_pnt, pnt]), sr) prev_pnt = pnt length = line.length from_pnt = line.firstPoint to_pnt = line.lastPoint return length, str(from_pnt), str(to_pnt), line def GetDist(pnt1, pnt2): import math return math.hypot(pnt2.X - pnt1.X, pnt2.Y - pnt1.Y) if __name__ == '__main__': main()‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ It will do this on the input polygon and a generalized polygon (set the variable generalize on line 5 with a proper value): It also creates an output featureclass with the shortest edges.

XanderBakker · Answer

I have used the code below in the past to find the longest edge of a polygon, but you could rewrite it to find the shortest edge. However, there could be some discussion on what an edge is or how this should be interpreted: def GetLargestLine(polygon, offset): max_length = 0 prev_pnt = None side = None sr = polygon.spatialReference polygon2 = polygon.generalize(0.1) for part in polygon2: for pnt in part: # print pnt if prev_pnt is None: pass else: if pnt is None: pass else: length = GetDist(pnt, prev_pnt) if length > max_length: max_length = length side = arcpy.Polyline(arcpy.Array([prev_pnt, pnt]), sr) prev_pnt = pnt length = side.length side = side.segmentAlongLine(offset, length-offset, False) return side, length‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ This was used to generate solar panels on roof tops. See document here (Spanish content): https://community.esri.com/docs/DOC-10095-evento-spx-esri-colombia-generaci%C3%B3n-de-paneles-solares-en-techos-bogot%C3…