two real input channels xy graph curve fitting

[xkinger]

i'm a new user with labview, now i have a problem with the xy graph

i use two real input channels as the x and y axis of xy graph, but whatever i change the sample rate, the curve is so bad.

i use a quene to mean the x,y data but the result is not true.

there are the pic and vi. i hope anyone can give me some corrections or advice, thank you so much.

[xkinger]

here is the vi.

[xkinger]

Anybody know?

thank you