Origin Ver. and Service Release (Select Help-->About Origin): 8.1 Pro SR3 Operating System: Windows7 x64 Professional
i have got a curve by using non linear fitting, but while i using the tangent plug-in to draw a tangent line, it can only display the offset but not show me the tangent line...why? can't the plug-in use in Origin 8.1 pro?
I tried both tangent tools in 8.1 SR3 and both worked. I am not sure what you mean by 'offset' since neither tool has an 'offset'. To set the tangent line(s) with either tool, you must double-click or press Enter.