how to find nearest value to zeros?

i want to write a code to find a time between two values which are nearest one to zeros because i dont have any zeros in my signal.and I dont have any function I have just y values and time values.and between that time wich value of y is exist.thanks

Answer 1

[dpb]

If the signal crosses zero, look at

doc fzero

Otherwise, if is all positive the point nearest zero is simply

[ymin,ixmin]=min(y);

Obviously if y<0, min is max or use abs(y). Also, if is monotonic,

doc interp1  % to find intersection closer than nearest computed value

Failing that, there's

doc fminbnd
doc fminsearch