RE: Clear or remove definitions including Subscripts
- To: mathgroup at smc.vnet.net
- Subject: [mg23154] RE: [mg23116] Clear or remove definitions including Subscripts
- From: "David Park" <djmp at earthlink.net>
- Date: Thu, 20 Apr 2000 03:21:22 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
> From: SANCHEZ DE LEON, Guillermo [mailto:gsl at fab.enusa.es] To: mathgroup at smc.vnet.net > Dear friends, > > If I write: > > In[1]:= Subscript[a, 11]; > In[2]:= Subscript[a, 12]; > > Q1: How I can Clear or Remove the previous definitions?. > Q2: Is it posible to clear at the same time all definitions with pattern: > Subscript[a, i] (* i=1,2,..*) > > I wish to avoid using Notation Package > > I have tested: > > In[3]: Clear[Subscript[a, 11]] > Message: Clear:: "ssym": a_11 is not a symbol or a string > > In[4]: Clear["\!\(a\_11\)"] > > But they don`t work > Here is a Mathematica notebook, which if you open and save, will produce a package called WollSubscripts. I wrote the package as a slight modification and extension of a suggestion first put forward by Carl Woll in MathGroup. It allows you to use subscripted symbols, even if the subscript has been given a value elsewhere. It also has routines for clearing the subscript variables and obtaining information on them. The package should be put in the AddOns/ExtraPackages/Algebra directory. Copy the text and paste it into an empty notebook. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ (*********************************************************************** Mathematica-Compatible Notebook This notebook can be used on any computer system with Mathematica 4.0, MathReader 4.0, or any compatible application. The data for the notebook starts with the line containing stars above. To get the notebook into a Mathematica-compatible application, do one of the following: * Save the data starting with the line of stars above into a file with a name ending in .nb, then open the file inside the application; * Copy the data starting with the line of stars above to the clipboard, then use the Paste menu command inside the application. Data for notebooks contains only printable 7-bit ASCII and can be sent directly in email or through ftp in text mode. 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Subscript \ definitions can be defined. The additional routines ClearSubscripts and \ SubscriptInformation are also provided.\>"\)], "Input", InitializationCell->True], Cell[BoxData[ \(\(ClearSubscripts::usage = "\<ClearSubscripts[sym1, sym2,...] will \ clear all Subscript definitions based on the symbols.\>";\)\)], "Input", InitializationCell->True], Cell[BoxData[ \(\(SubscriptInformation::usage = "\<SubscriptInformation[sym1, sym2,...] \ will print the Subscript definitions based on the symbols.\>";\)\)], "Input", InitializationCell->True], Cell[BoxData[ \(Begin["\<`Private`\>"]\)], "Input", InitializationCell->True], Cell[BoxData[{ \(\(SetAttributes[ ClearSubscripts, {HoldAll}];\)\), "\[IndentingNewLine]", \(ClearSubscripts[a__]\ := \[IndentingNewLine]\ Module[{b}, \[IndentingNewLine]DownValues[Subscript]\ = Cases[DownValues[Subscript], \((b_\ :> \ _)\)\ /; \ FreeQ[b, HoldPattern[ Subscript[ Alternatives[a], \ __]]]]; \[IndentingNewLine]SubValues[ Subscript]\ = Cases[SubValues[Subscript], \((b_\ :> \ _)\)\ /; \ FreeQ[b, HoldPattern[ Subscript[ Alternatives[ a], \ __]]]];\[IndentingNewLine]]\)}], "Input", InitializationCell->True], Cell[BoxData[{ StyleBox[\(SetAttributes[SubscriptInformation, \ {HoldAll}];\), FormatType->StandardForm], "\n", StyleBox[\(SubscriptInformation[syms__]\ := \[IndentingNewLine]\ Module[{PrintDownValue}, \[IndentingNewLine]PrintDownValue[\(Verbatim[ HoldPattern]\)[a_]\ :> \ b_]\ := \ Print[HoldForm[ a\ = \ b]]; \[IndentingNewLine]PrintDownValue\ /@ \((DeleteCases[ Join[DownValues[Subscript], SubValues[Subscript]], \ \((b_\ :> \ _)\)\ /; \ FreeQ[b, HoldPattern[ Subscript[ Alternatives[ syms], \ __]]]])\);\[IndentingNewLine]]\), FormatType->StandardForm]}], "Input", InitializationCell->True], Cell[BoxData[ \(End[]\)], "Input", InitializationCell->True], Cell[BoxData[ \(Protect[ClearSubscripts, SubscriptInformation]\)], "Input", InitializationCell->True], Cell[BoxData[ \(EndPackage[]\)], "Input", InitializationCell->True] }, Open ]] }, Open ]] }, FrontEndVersion->"4.0 for Microsoft Windows", ScreenRectangle->{{0, 1280}, {0, 943}}, AutoGeneratedPackage->Automatic, ScreenStyleEnvironment->"Working", InitializationCellEvaluation->False, WindowSize->{591, 571}, WindowMargins->{{Automatic, 94}, {Automatic, 21}}, PrintingCopies->1, PrintingPageRange->{Automatic, Automatic}, PageHeaders->{{Cell[ TextData[ { CounterBox[ "Page"]}], "PageNumber"], Inherited, Cell[ TextData[ { ValueBox[ "FileName"]}], "Header"]}, {Cell[ TextData[ { ValueBox[ "FileName"]}], "Header"], Cell[ TextData[ { ValueBox[ "Day"], " ", ValueBox[ "MonthName"], " ", ValueBox[ "Year"]}], "PageNumber"], Cell[ TextData[ { CounterBox[ "Page"]}], "PageNumber"]}} ] (*********************************************************************** Cached data follows. 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