Sampling Data (Urgent help needed)

Hello, everybody,

I have a question regarding sampling data.

I have a case where I use

x = linspace(0, 1, N);

and after calculations I did plot of equation with, let say U

plot(x,U);

I want to sample data in long vector when x = 0.22 but let say with linspace I don't get this value, but in the plot I do have it. Note that function is time dependent, and I intend to use long vector with fft and plot...

Is there way to find or use plot or any trick to get what I want.

Thanks in advance.

Regards, Feruz

Answer 1

[Wayne King]

You can also change the increment between the values in your x vector so that you do have 0.22.

x = 0:.01:1-0.01;
U = exp(-x);
x(23)
U(23)

% or  
x = linspace(0,0.99,100);
U = exp(-x);
x(23)
U(23)

[Feruz]

Thanks for answer...

Though, I want to check

vc = [];

if (x == 0.22)

vc = [vc U]

in that form, not by index, but by the value.

Making everything manually hurts, so that I was wondering or wanted to make it automate, so that in any value of x in that interval I can sample...

[Walter Roberson]

You are never going to get an x of exactly 0.22.

http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F