DSP- difference between Differential and Difference equation

EDAboard.com Forum Index -> Digital Signal Processing -> DSP- difference between Differential and Difference equation

Author

Message

Faizan Tahir Butt

Joined: 21 Nov 2008
Posts: 17

23 Nov 2008 11:06 difference equation dsp

What is the difference between a Differential equation and a Difference equation?

Google
AdSense
Google Adsense

23 Nov 2008 11:06 Ads

mathuranathan

Joined: 11 Sep 2006
Posts: 247
Helped: 29
Location: India

24 Nov 2008 6:29 Re: DSP

Differential equation is used to find an unknown value from a set of other values and derivatives.
Example : equation to calculate acceleration (a) of a mass from the distance traveled (s) and time taken (t).

a = d²s/dt²

This is a second order differential equation

Difference equation is type of recurrence equation. It is used to find the value of a variable
recursively. Example

y(n) = x(n)+y(n-1)

this equation implies the present value of y is calculated from present value of x and past
value of y. This is an example of recurrence equation.

Recurrence equation to print a series of Fibonacci numbers is also a difference equation.

xulfee

Joined: 27 May 2008
Posts: 434
Helped: 32
Location: Pakistan

25 Nov 2008 7:20 Re: DSP

differential equations must conatian terms with their rate of change like dy/d,it may also contain terms with intergeral ∫f(x)dx,these equations r mostly used for analog system containing capacitors,resistors n inductor kind of things.
on other hand difference equations r like this y[n] = x[n]+ x[n-1]-y[n-1] kind of terms,these equaions r used for digital systems