zoron@en.ecn.purdue.edu (Soren M Burkhart) (12/09/90)
I have an HP-28S and I wanted to know if there were any programs out
there that did convolutions. I didn't see anything in the reference manuals.
If there aren't any for the 28S how about the 48SX? THanks in advance.
Soren Burkhart
zoron@en.ecn.purdue.edu
(nothing fancy just plain and simple :>)bobc@hplsla.HP.COM (Bob Cutler) (12/11/90)
Here's a program I've been using on my 28s. There's probably a more
efficient way to write a convolution program, but what the heck, it works.
CONV expects two vectors on the stack as input and returns a vector.
For example,
To solve:
(3x^2 +2x + 1)( x + 5)
Enter:
[3 2 1] [ 1 5] 'CONV'
The result is
[ 3 17 11 5] or (3x^4 + 17x^2 + 11x + 5)
Enjoy,
Bob Cutler
KE7ZJ
Hewlett-Packard
Lake Stevens Instrument Division
Everett, WA 98205
----------------------------------------------------------------------
'CONV'
<< -> A
<< -> B
<< A SIZE LIST-> DROP
B SIZE LIST-> DROP
+ 1 - -> N
<< A N 1 -> LIST
RDM -> A
<< B N 1 ->LIST
RDM -> B
<< 1 N FOR
I 0
1 I FOR
J A J GET B I J - 1 + GET * +
NEXT
NEXT
N -> ARRY
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