MATLAB finding x according to y on graph?

Question

Hi there,

I have a amplitude vs time graph on matlab. I want MATLAB to tell me where on the X axis when Y is greater than 0.5. How would I go about doing that.

Trying to learn MATLAB,

Thanks.

Answer 1

Hello Free...To get any response on a function where a line would cross the X axis you need a slope... The standard form is y=mx+B

...Now all that being said the graph of the line y> or = to .5 is fine with me ..It just never crosses the X axis .its just a straight line at .5 y ..Now if your problem says the amplitude drops to a negative or zero at some time (like five seconds) then you can guess that 5 is the intersection of the X axis..Well hope that helped ya...From the E

Answer 2

No, the graph never crosses the y-axis. each and every time a graph crosses the y-axis, its y-coordinate is 0. yet while xy = a million, then y won't be able to be 0, because of the fact something circumstances 0 is 0 (not a million). So the graph of xy = a million never crosses the y-axis.

Answer 3

in matlab, as my knowledge, you cant take a graph as input.



probably you can derive or assume the equation by looking your graph(standard equations).



if graph is random(noise), then you have to use any mathematical methods to deduce the equation. numerical analysis or statistics or estimation(random theory).