Has anyone here used the software Tableau? I am working on building a report in it, but am having a lot of difficulty getting a calculation to sum. The program either tells me that the data has to be from the same data source or it tells me that the calculation is already aggregated and cannot be further aggregated. I'm at my wits end. I don't know what else to do with this to get the calculation that I need and was hoping there might be someone here who has had the same problem with this software.