Re: Problems creating a package file
- To: mathgroup at smc.vnet.net
- Subject: [mg77085] Re: Problems creating a package file
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Sun, 3 Jun 2007 06:08:02 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- References: <f3r92a$sgg$1@smc.vnet.net>
chuck009 wrote:
> Hello everyone.
>
> I'd like to create my own package of some plotting routines but I'm having problems getting routines to work within the package. I suspect my context is not right. I created PlotRoutines.m via File/SaveAsSpecial/PackageFormat and placed it in a PlotUtilities directory within the ExtraPackages directory:
>
> (*
> PlotRoutines.m
>
> Package for plot routines *)
>
> BeginPackage["PlotUtilities`PlotRoutines`"];
>
> TagPoints::usage = "Tag Polygons with '1' which satisfy passed inequality"
>
> Begin["`Private`"];
>
> TagPoints[inequality_][p_] :=
> Block[{x, y, z}, {x, y, z} = p; If[inequality, {p, 1}],{p, 2}]];
^^^^^ ^^^^^^^^^^^^^ ^
(1) (2) (3)
(1) -> Block is not needed. Should use Module anyway.
(2) -> Useless assignment since x, y, and z are not used.
(3) -> Extraneous square bracket: end the If statement here.
>
> End[];
>
> EndPackage[];
>
> It takes a Graphics3D object and tests each coordinate of each Polygon matching the search criteria specified in the inequality and is suppose to append either a 1 or a 2 to each coordinate. I'd call it as:
>
>
> << PlotUtilities`PlotRoutines`
>
> p1=Graphics3D[Plot3D[some plot here]]
>
> p1 /. Polygon[pts_] :> Polygon[TagPoints[z â?¥ 2] /@ pts];
^^ ^^
(4) (5)
(4) -> z has no value here.
(5) -> The second argument of TagPoints is missing ==> TagPoints is
never executed.
> However it doesn't update the polygons and I know it works when I create the TagPoints function within the notebook. Also, I noticed when I first create the *.m file, Mathematica adds (* *) to the file which I remove. Not sure what to do. Can someone help me?
>
You could write your package as suggested below.
(** Beginning of the file **)
(*PlotRoutines.m Package for plot routines*)
BeginPackage["PlotUtilities`PlotRoutines`"];
TagPoints::usage = "Tag Polygons with '1' which satisfy passed inequality"
Begin["`Private`"];
TagPoints[True][p_] := {p, 1}
TagPoints[False][p_] := {p, 2}
End[];
EndPackage[];
(* End of the file *)
Save the above in a .m file. Now we can test it as in the following:
In[1]:=
<< "PlotUtilities`PlotRoutines`"
In[2]:=
$ContextPath
Out[2]=
{"PlotUtilities`PlotRoutines`", "Global`", "System`"}
In[3]:=
Information["TagPoints", LongForm -> False]
"Tag Polygons with '1' which satisfy passed inequality"
In[4]:=
p1 = Graphics3D[Plot3D[x*Sin[y] + y*Cos[x],
{x, 0, 2*Pi}, {y, 0, Pi}]];
p1 /. Polygon[pts_] :> Polygon[
(TagPoints[#1[[3]] >= 2][#1] & ) /@ pts];
In[6]:=
(Short[#1, 6] & )[FullForm[%]]
Out[6]//Short=
Graphics3D[List[Polygon[List[List[List[0.`,0.1308996938995747`,0.\
1308996938995747`],2],List[List[0.`,0.`,0.`],2],\[LeftSkeleton]1\
\[RightSkeleton],List[List[0.2617993877991494`,0.1308996938995747`,0.\
16061107220589643`],2]]],\[LeftSkeleton]575\[RightSkeleton]]\
,List[Rule[PlotRange,Automatic],\[LeftSkeleton]30\[RightSkeleton],\
\[LeftSkeleton]1\[RightSkeleton]]]
Regards,
Jean-Marc