Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Name of some special functions

  1. May 7, 2014 #1
    I'd like of know if the following functions have name: Y(σ), H(σ) X(σ), Y(iω), X(iω), Y(s), X(s).

    PS, I suppose that H(σ) must be the "exponential response"...
  2. jcsd
  3. May 7, 2014 #2
    Is there a context for these? They can be called whatever you'd like to call them without context.
  4. May 7, 2014 #3


    User Avatar
    Science Advisor
    Homework Helper

    Y and H are usually types of Bessel functions, but I don't recognize X as a standard notation for anything.
  5. May 7, 2014 #4


    Staff: Mentor

    Without some context we can't give any definitive answers. H is also used for the Heaviside step function. Y(s) is used for the Laplace transform of some function y(t). Same for X(s), but in this context, x, y, X, and Y are just function names with no special meaning.
  6. May 8, 2014 #5
  7. May 8, 2014 #6


    User Avatar
    Science Advisor

    Those are all defined in the first page you cite. "X" is the Laplace transform of whatever "input function" you have and "Y" is the Laplace transform of its "output function". H is the ratio [itex]\frac{Y}{X}[/itex].
  8. May 8, 2014 #7
    Not always those functions has the same name, for example, h(t) = "impulse function", H(s) = "transfer function" and H(iω) = "frequency response". For this I asked if the functions in my first post have special names...
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook