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 >> >> >> >> >> >>