第一次知道这个用法,呵呵。查了下help
plot(X1,Y1,X2,Y2,...) plots the vectors Y1 against X1, Y2 against X2, and so on. Vector pairs must be the same length and the list must consist of an even number of vectors.
Plot commands can include NaN and inf values. When NaNs or infs are encountered, Simulink software stops drawing, then begins redrawing at the next numbers that are not NaN or inf.