【答案】应助回帖

10楼: Originally posted by tang-bo001 at 2011-12-30 08:38:00:
t=data(:,1);x=data(:,2);y=data(:,4);
bx=find(diff(sign(diff(x)))>0)+1;
by=find(diff(sign(diff(y)))<0)+1;
bb=find(abs(diff(x(bx)))>4);
figure;
plot(t,x,t,y,'g-',t(bx(bb)),x(bx(bb)),'r ...