public void ProcessData(IMatrixData mdata, Parameters param1, ref IMatrixData[] supplTables, ref IDocumentData[] documents, ProcessInfo processInfo) { int[] stringCols = param1.GetParam <int[]>("Text columns").Value; if (stringCols.Length == 0) { processInfo.ErrString = "Please select some columns."; return; } mdata.UniqueValues(stringCols); }