MaplePrimes - answers and comments on Question, How to avoid calling packages multiple times

For details on initialization files you can

John May — Mon, 30 Aug 2010 23:42:41 Z

For details on initialization files you can see ?CreateMapleInitializationFile

You could try to make a worksheet script for your students. I know the following Maple code works in Linux to set up the init file so that it will automatically run 'with' after each restart. I think it works in Windows, but I have not tested it.

 # Uncomment the approriate line below:
 #mapleinitfile := cat(kernelopts(homedir), kernelopts(dirsep), ".mapleinit"); # Linux, Solaris, and Mac
 #mapleinitfile := cat(kernelopts(homedir), kernelopts(dirsep), "maple.ini"); # Windows (untested)

 FileTools:-Copy(mapleinitfile, cat(mapleinitfile, ".mpl.bak"));
 FileTools:-Text:-Open( mapleinitfile, 'append');
 FileTools:-Text:-WriteLine(mapleinitfile, "with(PackageName):");
 FileTools:-Text:-Close( mapleinitfile );

command line options

Joe Riel — Tue, 31 Aug 2010 04:03:01 Z

John's solution is interesting, but I wouldn't want a worksheet to mess with my initialization file. There is another way to do what you want, however, as with most things, it is easy to do in linux, and a bit more challenging in Windows.

If you launch the Maple gui from the command line, you can use the -c option to assign a command that the Maple engine executes when it starts up, and reexecutes following a restart. So if you wanted to load a package few packages you could do (in linux)

$ maple -x -c 'with(plots)' -c 'with(LinearAlgebra)'

The -x option says to launch the gui, each -c option defines a command that is executed. For a more complicated sequence of commands, you could put them into a text file, say restart.mpl, and then do

$ maple -x -c 'read("restart.mpl")'

The Maple commands in restart.mpl will be read and executed at startup and following each restart.

Getting this to work in Windows is doable, I believe, though I don't use Windows so cannot verify.

customized restart command - first ideas

Doug Meade — Tue, 31 Aug 2010 07:27:22 Z

Here's an idea that I hope somewill can turn into a viable answer.

What I envision is a procedure that captures the list of loaded packages, executes the restart, and then reloads the packages.

The packages command provides the list of currently loaded packages. So, what you want to execute is, essentailly:

restart; map( with, packages() );

where the value of packages() is determined before the restart is executed.

Here's my naive attempt to implement this idea:

MyRestart := proc()
  local _CMD;
  _CMD := sprintf( "restart; map( with, %a );", packages() );
  parse( _CMD );
  return NULL;
end proc;

Usage would be:

MyRestart();

This does not work because parse executes only one command each time it's called. So, the offset option has to be used, maybe something like this:

MyRestart := proc()
   local _CMD;
   _CMD := sprintf( "restart; map( with, %a );", packages() );
   parse( _CMD, 'offset'=0, statement );
   parse( _CMD, 'offset'=10, statement );
   return NULL;
 end proc;

(There's no need for lastread because we know there are exactly 2 statements in this string.

This has several problems. First, restart can be executed only at the top level, not in a proc.

That's as far as I got with this tonight. I'll bet by the time I wake up someone will have a way to do this. I just hope my ideas are helpful in getting to that point.

Doug

---------------------------------------------------------------------
Douglas B. Meade  <><
Math, USC, Columbia, SC 29208  E-mail: mailto:meade@math.sc.edu
Phone:  (803) 777-6183         URL:    http://www.math.sc.edu

Unassigning user assigned names

Preben Alsholm — Tue, 31 Aug 2010 14:52:43 Z

Here is another idea.

The procedure _RemoveMyAssignments unassigns all user assigned names, but because of the leading underscore, it doesn't unassign the name _RemoveMyAssignments.

If the procedure is placed in a library, it won't be unassigned either. See the help for 'anames'.

_RemoveMyAssignments:=proc() local L;
L:=map(convert,[anames('user')],string);
unassign(op(map(parse,L)))
end proc:

p:=plot(sin);
tr1:=87;
t[6]:=14;
M:=Matrix(3,3,(i,j)->i+j);
_RemoveMyAssignments();
p,tr1,t[6],M;
eval(t);
eval(_RemoveMyAssignments);

re-initialization

pagan — Tue, 31 Aug 2010 15:44:15 Z

We should note Erik's own comment that one of the benefits of having the `with` inside the worksheet is that it makes the worksheet portable amongst other users. It makes sense: if the worksheet needs the packages loaded in order to work as intended, then it is the worksheet which should somehow bring about the `with` loading.

Having said that, of all the approaches mentioned I like Joe's most, to use an option of the GUI's launcher. At some universities the IT support is somehow able to install customized application launchers on students desktops. It could be done for a class, too, even if by running an insall script just once at the start of the semester.

And repeated -c options might not be the only way, using the launcher. isn't there also a -i option, to force use of a particular file as the initialization file instead of the usual maple.ini? Or is that only on Unix?

Trying to somehow clear the entire environment, by removing all assignments, etc, seems hard to do exhaustively. Erik only mentioned inadvertant assignments to variables. But there are also remember tables and caches of system routines to consider. That includes both remember tables of evalf, limit, etc, but also mistakes like sin(x):=2.3 which don't show up in anames(user).

Repeat Autoexecute

herclau — Tue, 31 Aug 2010 16:00:44 Z

Download Autoexecute.mw