Latest Contributions by DuncanHornby

OK all, Here is a tough one. I've written some VBA (because pythons method of spawning sub-processes meant my code was going to take 62 days...) and I've noticed the memory usage just keeps on creeping up. At one point I use the geoprocessor to call the Select Tool to create a new shapefile containing 1 point (Which is then used as a pour point for catchment generation) I create and set the geoprocessor as such: Set pGP = New GeoProcessor With pGP      .OverwriteOutput = True      .AddOutputsToMap = False      .LogHistory = False      .TemporaryMapLayers = True End With I call the tool as such: query = Chr(34) & "ID" & Chr(34) & " = " & CStr(ID) With pVA     .RemoveAll     .Add pFeatureLayer_Sites.FeatureClass     .Add "in_memory\tempSP"     .Add query End With pStatusbar.Message(0) = "Extracting a single site to in_memory" Set pGPR = pGP.Execute("Select", pVA, Nothing) Set pFeatureClass = pGPUtils.OpenFeatureClassFromString(pGPR.GetOutput(0).GetAsText) Set pGeoDataSetPP = pFeatureClass I release the memory as such: With pGPUtils     .RemoveInternalLayer "tempSP"     .ClearInMemoryWorkspace     .RemoveInternalData     .ReleaseInternals End With and I even kill off the geoprocessor within the loop as such: Set pGP = Nothing pGPUtils.ReleaseInternals In Arcmap Tools > options: Log geoprocessing is ticked off, results are temporary and results management is set to "Never Save" So at all stages I say NO results, NO logging yet the Select tool still adds an entry in the ArcToolbox results Tab which overtime consumes memory. I need to run this tool a lot of times for a long time but I just can't make ArcMap not Log a result! Any ideas, any undocumented tips or is this a bug? Duncan ... View more

All, Below is a python script I developed for extracting out elevation information for a point dataset. Basically it gets a list of ID's from a table (the barrier ID table) then for each ID is selects 2 points from a point Featureclass, it then snaps them to the flow accumulation grid, extracts the values and writes the min and max value to an output table. The code runs fine but eventually crashes after 3 or 4 hours. I then have to compact the personal geodatabase and restart the code from the point it crashed. What I've noticed is that the personal geodatabase just keeps on getting bigger until it hits the 2GB limit (hence the code failing). So my question to all you python gurus is how do I change my code to stop this annoying behaviour? I tried putting a "compact" in every 500th ID but it comes up with an error. ''' Description: Extracts the minimum and maximum DEM values for each barriers              upstream and downstream limit Constraints: Designed to work only in the 9.3 ArcGIS system. Author: Duncan Hornby Email: ddh@geodata.soton.ac.uk Created: 6/8/2010 ''' # Import system modules import sys, arcgisscripting # Create the Geoprocessor object & set any environment settings gp = arcgisscripting.create(9.3) gp.SetProduct("ArcView") gp.CheckOutExtension("Spatial") gp.Workspace = "c:\\temp\\" gp.cellSize = "50" gp.OverWriteOutput = 1 # Set any objects and variables tempRaster = "snapIntPnt" tempRaster2 = "ExtDEM" tempLayer = "tempPointLayer.shp" pgd = "G:\LiveData\UC1168_Sediment_WQ0128\Vector\pGDB93_UC1168_Output.mdb" # Get parameters BarrierIDTable = gp.GetParameterAsText(0) IntersectionPointLayer = gp.GetParameterAsText(1) FlowAccum = gp.GetParameterAsText(2) DEM = gp.GetParameterAsText(3) Output = gp.GetParameterAsText(4) gp.SnapRaster = FlowAccum # Create a cursor over the barrier ID table rows = gp.SearchCursor(BarrierIDTable,"","","OBSTRUCTID","") row = rows.next() # Iterate through the rows in the cursor while row:     # Get barrier ID     bID = row.GetValue("OBSTRUCTID") ##    # Check to see if we should compact the geodatabase at every 500th ##    if bID%500 == 0: ##        gp.AddWarning("Compacting GeoDatabase...") ##        gp.Compact_management(pgd)     gp.AddMessage("Processing Barrier: " + str(bID))     # Select all the intersection points that belong to this barrier     gp.SetProgressorLabel("Selecting intersection points...")     gp.SelectLayerByAttribute_management(IntersectionPointLayer,"NEW_SELECTION","[OBSTRUCTID] = " + str(bID) + " AND [UseAsSlopeLimit] = 'Y'")     # Convert selection to a layer so we can get an extent     gp.SetProgressorLabel("Getting extent of selection...")     gp.CopyFeatures_management(IntersectionPointLayer,tempLayer)     obj = gp.Describe(tempLayer)     gp.Extent = obj.Extent     del obj # Destroy object         # Snap selected points to flow accumulation grid     gp.SetProgressorLabel("Snapping selected points to flow accumulation grid...")     gp.SnapPourPoint_sa(IntersectionPointLayer,FlowAccum,tempRaster,"25","OBSTRUCTID")     # Now extract the DEM values from the pre-prepared raster layer     gp.SetProgressorLabel("Extracting DEM cells...")     gp.ExtractByMask_sa(DEM,tempRaster,tempRaster2)     # Extract the properties from this raster     gp.SetProgressorLabel("Reading raster properties...")     resultObj = gp.GetRasterProperties_management(tempRaster2,"MINIMUM")     zMin = resultObj.GetOutput(0)        resultObj = gp.GetRasterProperties_management(tempRaster2,"MAXIMUM")     zMax = resultObj.GetOutput(0)     gp.AddMessage("Elevation - Min:" + str(zMin) + " , Max: " + str(zMax))     del resultObj # Destroy object         # Write data to output table     gp.SetProgressorLabel("Updating output table...")     InsertRows = gp.InsertCursor(Output) # Create insert cursor for table     aNewRow = InsertRows.NewRow()     aNewRow.SetValue("OBSTRUCTID",bID)     aNewRow.SetValue("MinEle",zMin)     aNewRow.SetValue("MaxEle",zMax)     InsertRows.InsertRow(aNewRow)     InsertRows.Reset()        del aNewRow # Destroy object     del InsertRows # Destroy object         # Get next Barrier ID        row = rows.next() # Return extension license gp.CheckInExtension("Spatial") ... View more

All, We have just accquired the new ArcGIS 10 and I have been experimenting with model builder. I'm a big fan in documenting such tools as I never remember why, when & how I did things 6 months ago! In 9.3 when you were in model builder you could right-click on a process (the yellow box) and "edit documentation". This does not exist any more in ArcGIS 10, or does it and you have to access it via some other route? In ArcCatalog 10 you can add documentation to a parameter through Item description but I have yet to find a way how to document the process. Has this been dropped? Duncan ... View more

All, I've decided to post this question here as I think this is my best chance in getting an answer.  I've got VB .net 2005. I'm familiar with creating a class with properties and methods and can even use interfaces. I understand overloading and simple examples of inheritance. I would like to replicate a behaviour of ArcObjects that I come to love and know, the QueryInterface.  So first just look at the simple example below using ArcObjects. ' Retrieve a Polygon from a collection Dim pPolygon as IPolygon pPolygon = aCollection.Item(0) Dim pArea as IArea pArea = pPolygon 'QI Msgbox pArea.Area pArea could have been pointed to an Envelope or Ring not just a Polygon.  I've been playing around with VB .Net trying to create classes that behave in the same way. I'm not talking about ArcObjects now just some class that I imagined up. How do you create a Class that you can point to another class. Take another example if you create a pointer of type IFeatureLayer and point it to a Layer you can access the search cursor but this not a method of ILayer. I was wondering if any of you hardcore coders had a trivial example of a VB .Net project that shows custom classes (nothing to do with ArcObjects) behaving this way?  Does VB .Net even allow you to develop objects this way? Duncan ... View more

All, I was wondering if anyone has experienced the following behaviour in Arcpad 8? I have some tiffs each with a tfw and prj file. On my Pocket Loox device if I add the rasters first then a layer from an AXF geodatabase ArcPad is happy. When I add the the AXF layer (and yes it does have the same projection) then my rasters, ArcPad says for each raster that it does not have projection information do I want to assume its the same as the projection as set by the AXF layer! This is daft as obviously they do. Duncan ... View more