Extract coefs. and exponents from a list . Package problem
- To: mathgroup at smc.vnet.net
- Subject: [mg30684] Extract coefs. and exponents from a list . Package problem
- From: guillerm at aida.usal.es (Guillermo Sanchez)
- Date: Sat, 8 Sep 2001 02:22:27 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Dear group
(*I wish extract the coeffs and the exponents from expresion as follow*)
list1=0.1 Exp[-0.3 t]+0.2 Exp[-0.1 t]+0.4 Exp[-0.4 t];
(*This function works*)
ExtractCoef1[list_]:=
Block[{f,g,a,b},f[a__]:={a};
g[b__]:={b};{(#1/.a_*Exp[b_*t]\[Rule]a&)/@
f@@list,(#1/.a_*Exp[b_*t]\[Rule]b&)/@g@@list}]
ExtractCoef1[list1]
(*out[]:{{0.4`,0.1`,0.2`},{-0.4`,-0.3`,-0.1`}}*)(*it works*)
(*But, if I use this function inside a package it doesn`t work*)
BeginPackage["test`test`"];
ExtractCoef::usage="ExtractCoef[test]";
Begin["`Private`"];
ExtractCoef[list_]:=
Block[{f,g,a,b},f[a__]:={a};
g[b__]:={b};{(#1/.a_*Exp[b_*t]\[Rule]a&)/@
f@@list,(#1/.a_*Exp[b_*t]\[Rule]b&)/@g@@list}]
End[];
Protect[ExtractCoef];
EndPackage[];
ExtractCoef[list1](*It doesn´t work*)
(* question 1: I wist fix this problem,any help?,
question 2: Could any body build a expresion easier?*)