Hello, I want to experiment with vtkChartXY and tcl, but when I add this line to my script: vtkChartXY chart I get this error: Error in startup script: invalid command name "vtkChartXY" while executing "vtkChartXY chart" (file "prueba.tcl" line 21) My environment is: Ubuntu 12.04 + VTK 5.8. Could someone tell me what can I do from here? -- Mario