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From: jsims@vuse.vanderbilt.edu (J. Robert Sims)
Newsgroups: comp.sys.handhelds
Subject: discrete _unit_ impulse function (Was: Re: hp48: User-definedderivative problems
Message-ID: <9102261313.AA16984@vuse.vanderbilt.edu>
Date: 26 Feb 91 13:13:19 GMT
Lines: 29
Return-path: <jsims@vuse.vanderbilt.edu>
To: handhelds@gac.edu

>> Hello world!
>>
>> We have some problems to define discrete Heaviside step function
>> U(t) and it's derivative Unit impulse SIGMA(t) in the same
>> directory, and after that use: 'dt(U(5*t))' EVAL.
>>
> 
>Maybe you're talking about a different Unit impulse function, but the one
>I'm familiar with (what my Signals book and Probability and Random Variables
>book call delta(t)) is defined as a "function" having the following
>properties...
> 
>delta(t) = 0, t<>0
>and the integral of delta(t) with respect to t over all time equals 1.
> 
>delta(0) approaches infinity, not 1. The integral of it from 0- to 0+ (or a
>y interval containing 0) does equal 1.
> 
>-Randy Weems
>RJW0180@TNECH.BITNET

The unit impulse function for _discrete_ processing is one at 0.  Otherwise it
is just called an impulse function.

For all the people who can't mail to hpcvbbs, the address is:
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Rob
jsims@vuse.vanderbilt.edu