Matlab simulation sometimes has errors. You can try to clear the history by typing "clear" in the window, or try to reopen the window. If it's not matlab's fault, another possibility is to see if the program is wrong. T=0:0. 1: 100 The length is 1000, that is, if the length is used, 1000 will appear. What is the specific problem still depends on the program to know, you can try these methods, if not, you can upload the source code!