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joe
Posts:
19
Registered:
9/24/09


Re: find meeting point
Posted:
Oct 3, 2009 4:47 PM


ImageAnalyst <imageanalyst@mailinator.com> wrote in message <4c956101539843e892f0de3935501613@a6g2000vbp.googlegroups.com>... > 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.
Hi Thanks for your Help and I undertstand your point of view. A problem is , I want to the point on the Time Axis , not just the solution of this equation.
Thanks



