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Re: find meeting point
Posted:
Oct 3, 2009 3:29 PM


On Oct 3, 3:07 pm, "joe " <courstele...@yahoo.fr> wrote: > "joe " <courstele...@yahoo.fr> wrote in message <ha80mt$9t...@fred.mathworks.com>... > > Hi > > I have to find the time (point ) where the signal (sinus) and the axis (i.e y=10)... > > > thx > > Hi > Here a example about this point > t=0:0.001:5; > S=sin(2*pi*t)+sin(20*pi*t); my signal > y=4; the point > plot(t,s,t,y,'k') > I want to know the point the different time where y meet S... > > thanks  That's easy. The answer is "never" since s never exceeds 2. Next time post code that will run. I had to fix three errors in your code to get it to run. In general you might look for something like aboveElements = (s > y); if you want to find those elements where s is above y. Most likely it will never exactly be equal so you have to know what you want. Realize here that you're dealing with quantized arrays. If you really want to know where y = s then you'll have to find the roots of the equation sy=0 and it the answer(s) may not lie exactly on array elements  it may lie in between elements.



