Latest Contributions by EdRollason

Hi, I have been calculating some raster surface volumes for a recent project.  Basically I'm calculating the volume of water displaced out of a floodplain by a new embankment so as to provide compensatory storage. Anyway, the results I have been obtaining do not make sense and do not appear to be correct.  I decided to check them with Cut/Fill but these results also don't seem to be right. I then decided to do a simple check on the functions.  I created a 50x50 2m res grid with a Z value of 1.  I created another grid of the same size with a Z value of 2 and the same resolution.  Cut/Fill correctly calculates that the volume between these rasters is 2500m3.  However, Surface Volume (when given the equivalent reference plane value of 2) gives me a value of only 2,304m3 - that's an error of nearly 10%. Can anyone shed any light on this?  Am I missing something really obvious? I have tried changing the 3d Analyst environment settings but nothing seems to have an effect. Any pointers much appreciated Cheers Ed ... View more

I have a string variable (AssetID_Val) which is assigned from a previous element of code.  I want to compare the variable against some set values and assign another variable according to the value of AssetID_Val. I assume that a select case is the best way of doing this but am not sure of the correct syntax.  I also want to introduce a wildcard character into the select case as AssetID_Val will have a variable number. This is what I've come up with so far but it isn't working: Select Case AssetID_Val     Case Is = "ND_*"     Set pStdAloneTbl = pMap2.StandaloneTable(0)     Case Is = "LK_*"     Set pStdAloneTbl = pMap2.StandaloneTable(1)     Case Is = "PG_*"     Set pStdAloneTbl = pMap2.StandaloneTable(2)     Case Else     MsgBox "Error"     pEditor.AbortOperation     Exit Sub End Select The * indicates a 3 digit number which will change each time.  I can't work out whether the error is with my Case syntax or with the introduction of the wildcard.  Help on both would be appreciated. Cheers Ed ... View more

Hi all, I am aware that VBA is dead but I am stuck using Arc 9.2 and the project is quick and dirty so I'm going with what I know. Also apologies if this is in the wrong forum, I haven't posted since the old forums for discontinued. The Background: I have a personal geodatabase in which there is a point featureclass with a unique text identification field called "Asset_ID". Also within the pDB is a large table containing the details of the assets, also with an Asset_ID field. The FC is joined to the table using this field. I need my user to be able to select a point within the GIS and then delete the point AND the associated data record using VBA (there are some other tools associated with the data which are all in VBA so I'm sticking to what I know). Using various threads in the old forum and my own experience I can delete the selected record and I have written code to get the Asset_ID value of the selected feature and then access the joined table. I am attempting to use iQueryFilter.Whereclause to select the matching record from the joined table using the SQL query and passing it the Asset_ID value from the selected feature as a string variable. The problem: The code works fine when I feed it a hard-coded string variable (for example ND_001). But when I try and replace the string with the variable the query returns FALSE and it selects everything for deletion. I have checked the variable value and this is correct, and it is definitely looking at the correct table, which does contain a field called "Asset_ID". I am therefore assuming that there is something wrong with my SQL query - this is backed up by the fact that giving it a string value works. Could anyone help? I attach the full code. However, the query is below: ' Make the query filter Set pQueryFilt = New QueryFilter pQueryFilt.WhereClause = "Asset_ID = '" & AssetID_Val & "'" ' Asset_ID is the name of the field - this is a text field ' AssetID_Val is the variable - this will be a text string e.g. "ND_001" ' the SQL is copied from a previous thread at present but I have tried several with no success! '#########FOR SOME REASON THIS SELECTS ALL THE VALUES IN THE TABLE!!!!!!!######### ' Perform the selection pTableSel.SelectRows pQueryFilt, esriSelectionResultNew, False ' Report how many rows were selected Set pSelSet = pTableSel.SelectionSet MsgBox pSelSet.Count If pSelSet.Count = 0 Then MsgBox "Unable to delete background data - no matching record found" Exit Sub End If Set pTable = pStdAloneTbl pTable.DeleteSearchedRows pQueryFilt ... View more

I have moved this thread to the Map Objects Forum as I believe this is the correct place for it. Sorry Mods ... View more

Recently my version of ArcMap 9.2 (with 3d Analyst & Spatial Analyst extensions) has become quite unstable.  When I attempt to use tools such as interpolate line and contour ArcMap begins to process but then freezes and crashes with a "ArcGIS has encountered a problem as is forced to close.." error message.  The size of the grid does not appear to be a factor as this occurs even with very small grids. This problem has occurred recently and without any other changes being made to the hardware or software of the computer.  Has anyone else had a similar issue with this abd been able to fix without doing a complete re-install (which is my next option)?  Cheers Ed ... View more