streamline function gives empty output

Hi, I am trying to get the streamlines using

verts=stream2(x,y,u,v,startX,startY)

but the output is always empty. Then I tried

quiver(x,y,u,v)

and this plots the velocity field nicely. I also

plot(startX,startY)

and the line is exactly where I want to plot the streamline. I am confused why I got an empty output with stream2. The variables x, y are not meshgrids, and I am not sure if this is becomes a problem for streamline calculation. Does anyone meet a similar problem before? Thanks.

[KSSV]

Attach your data....If it is empty that means, there is not streamline starting from the side you have mentioned.

[Tong Bo]

Data attached. There is velocity data where I wanted to plot the streamline. I guess the non-meshgrid is the problem.

Answer 1

[KSSV]

Try replacing NaN's in u, v with zero and use stream2.