Re: Returning rules from functions inside a package context
- To: mathgroup at smc.vnet.net
- Subject: [mg82452] Re: Returning rules from functions inside a package context
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Sat, 20 Oct 2007 05:59:58 -0400 (EDT)
- References: <ff9rjl$4mv$1@smc.vnet.net>
Hi,
the clean way is to add usage messages to all
the symbols, i.e.,
BeginPackage["A`"]
f::usage = ""
a::usage ="a is the symbol for the slope fitted by f[]."
Begin["`Private`"]
f[] := FindFit[{{0, 0}, {1, 1}}, a x, {a}, x]
End[]
EndPackage[]
The second way is to return a string
BeginPackage["A`"]
f::usage = ""
Begin["`Private`"]
f[] := Module[{fit,a,x},
fit=FindFit[{{0, 0}, {1, 1}}, a x, {a}, x];
{"Slope"-> a} /. fit
]
End[]
and the dirty way is
BeginPackage["A`"]
f::usage = ""
a::usage ="a is the symbol for the slope fitted by f[]."
Begin["`Private`"]
f[] := FindFit[{{0, 0}, {1, 1}}, Global`a x, {Global`a}, x]
End[]
Regards
Jens
Art wrote:
> The following question has been asked and answered in a variety of
> ways in this forum, but I am new to Mathematica and am still not sure what is
> best practice after doing Trace of various trivial statements for the
> past few hours.
>
> For example, I would like f[] below to return {a->1.}, not
> {A`Private`a->1.}.
>
> BeginPackage["A`"]
> f::usage = ""
> Begin["`Private`"]
>
> f[] := FindFit[{{0, 0}, {1, 1}}, a x, {a}, x]
>
> End[]
>
> EndPackage[]
>
> The use of Rule[] in different scoping constructs is confusing.
>
> Thanks.
>
>