My objective is to swap X,Y coordinates of feature classes using Python and arcgisscripting. Based on help examples, I managed to write script which reads and writes all geometry types.
The problem is with polyline geometry: for multipart lines, all parts are connected and they should be disjoint. It seems that connection between last vertex of one part is connected with first vertex of next part.
It's strange especially as script deals well with multipart polygons and polygons with void.
Am I missing something with multipart polyline geometry?
import arcgisscripting gp = arcgisscripting.create(9.3) gp.overwriteoutput = True gp.workspace = r"D:\Work\SwapXY.gdb" inFC = r"D:\Work\SwapXY.gdb\Line" desc = gp.Describe(inFC) shapeField = desc.ShapeFieldName #SHAPE field name shapeType = desc.ShapeType # Create FC for inserting swaped geometries (if not exist) ... try: rows = gp.SearchCursor(inFC) #open SearchCursor on input FC row = rows.next() outRows = gp.InsertCursor(outFC) #open InsertCursor on output FC #create Array object which will contain features vertices (other than points) vertexArray = gp.CreateObject("Array") while row: feature = row.getValue(shapeField) #get the SHAPE field into variable ##For point geometry there is another way of reading coordinates than for polyline/polygon if shapeType.upper() == "POINT" or shapeType.upper() == "MULTIPOINT": #this part works right else: #feature can have multiple parts - first goes iteration through parts partNum = 0 partCount = feature.PartCount while partNum < partCount: part = feature.GetPart(partNum) #the output is Array of points pnt = part.next() #take first point from Array of points #iterate through all points in array while pnt: #for each geometry create new POINT obj and assign swapped Y, X. Then add vertices to ARRAY vertex = gp.CreateObject("Point") vertex.X = pnt.Y vertex.Y = pnt.X vertexArray.add(vertex) pnt = part.next() #If pnt is null, either the part is finished or there is an interior ring if not pnt: pnt = part.next() if pnt: print "Interior:" partNum += 1 newFeature = outRows.newRow() newFeature.shape = vertexArray #assign ARRAY filled with points to shape field outRows.insertRow(newFeature) vertexArray.RemoveAll() #clear ARRAY before processing new geometry row = rows.next() except: print gp.GetMessages()
In fact script doesn't work for polygons with more than one interior ring. So the problem is wider than I thought.
In polygon case, I've found that null point between exterior and interior rings should be inserted. But when
gp.CreateObject("Point") is inserted, a point with coordinates (0,0) is added.