I have a simple tecplot question: Right now I wanna plot a straight line on a 2D contour plot. I tried load data, but it does not work. Could anyone give me some hints? many thanks.

Maybe you can add a new frame and plot the line on the new frame and then link this frame with the contour frame. They will be in one picture then.

try to create 1D zone, it should work!!!

There are at least two possible approaches. Firstly, as Bruce mentioned, you can create a second Frame, in which to embed your line by Loading A DataSet. You must then resize and move one of the plots so that the contours and the straight line are juxtaposed the way you want them. If you go to print a hardcopy, you must Pop one of the Frames, so you can pick which Frame you prefer to have on top. Then you must Edit the Frame properties of the current (top) Frame to make the Background transparent, so that it does not hide the other plot when you print.

The other possibility is to add a Polyline to the current Frame. This used to be done from the Style menu in version 8, but may be located in some other menu or tool icon in newer versions of Tecplot. You can make the endpoints of the Polyline snap to the mesh points while you pick them, or you can position the endpoints accurately by watching the x-y coordinates in the status bar as you try to pick the point. Or else you may be able to type in the (grid, not window) coordinates of the endpoints to be even more accurate.

I do not believe creating a 1D Zone will work in the same Frame. At least in older versions, all the Zones in a particular Frame had to be of the same type.

Thanks for your suggestion, but how to link the frame of the line to the frame of contour?