165 Reputation

6 Badges

16 years, 71 days

MaplePrimes Activity

These are replies submitted by ianmccr

@Mac Dude 

I am extremely grateful for your response and the effort you put into it. In fact, I am floored that you made so much an effort to answer my question. Five Star rating from me!

You are correct that I am looking for certain expressions that will cancel out leaving the final expression describing a geometric product. For some reason, the op command didn't come to mind, but now that I see how you are searching for the integers that identify the sub-expressions, it makes perfect sense. I expect I will have to play with the procedure to apply it to the output from my problem, but it looks like it should work.

I used the workbook installer exclusively after it became available, so I never created a standalone .mla for the package. I did include the maple source .mpl file in the workbook so someone more familiar with the earlier process could create an .mla from the source. I have tested that installation from maplecloud works in maple 2019 and later, but I haven't had any feedback from anyone besides yourself. I can email the code and help files as well.

The bulk of the code ran on Maple V, which I updated it to a module package and changed to the modern linear algebra packages. Of late, I have tested it extensively, and I haven't found any glitches in the basic geometric algebra procedures (yet).

@Mac Dude 

Sorry for the delay in responding to you very quick response to my question, but I have been trying without success  to come up with a suitable example. I realize the attached spreadsheet is not a good example, but my efforts to simply copy some of the results to another worksheet were unsuccessful.

This worksheet uses the Glyp2 (from maple cloud) which is an updated version of Joe Riel’s Glyph package written for Maple V.

By way of background I am engaged in some experimental math looking for some alternate expressions of the clifford product which could possibly illuminate the Plucker Conditions as expressed in geometric algebra. Basically, I would like to prove when a given homogeneous r-multivector is a r-blade without resorting to the standard proofs usually expressed in exterior algebra.

The attached worksheet shows some of the calculations for a 4-blade product derived recursively from the 3-blade product I have already established. Unfortunately, These expressions represent the clifford product in an 8-dimensional geometry with a arbitrary bilinear form. The B-terms are just the metric constants.

My real problem is that it is relatively easy to show the relationship globally, but I need to determine  which sets of expressions of the scalar product cancel in the larger expression. This will help me to identify how to transform the expressions I have generated recursively into ones which actually represent the terms of the clifford product.  Comparing pieces of these expressions with each other is more than a little tedious and error-prone.

I am looking for a method to take the results from a trial symbolic expression representing a possible term and searching for it in a larger expression. (So I can see how the underlying algorithm actually processes the terms.) The final calculation shows an example of the terms that I would like to search and remove.

Can you suggest an approach to working with these large expressions. The following worksheet shows the kind of expressions I am trying to manipulate.


@TechnicalSupport . I installed the update as soon as it was released, but it didn't change the problem. This condition usually occurs after Maple has been opened for a number of hours. I tend to keep maple open and minimized for quite a while when I'm working on something, even if I'm not actively using it. A simple shut down will clear up the problem, and the UI still works if I guess the area where the control is located.



I snipped everything except the area where the screen does not update properly. Note, this problem appeared about two hours after the startup.  If I try to access menus or items in the affected area, they do appear around the mouse cursor, and it is possible to use the items (blindly).  However, once the problem appears it can only be reset by doing a complete restart of maple. Note also, that each time windows is minimized and then restored, the blank area reappears.


I will grab another screenshot just as soon as the problem reoccurs.  Whenever I exit and restart, the problem disappears.  It usually starts after Maple has been open for awhile.


Live and learn! That works. Thank you so much.


As an additional learning opportunity, your code provides a good example of how to use the document properties. I have skimmed the help pages for document tools and help tools previously, but their actual usefulness was not evident a.t the time. Now I get it!


I would have been really pleased if I had found this tutorial when I first searched for help on help.

@Joe Riel

Object encapsulation seems to be implemented in Maple in much the same way that it was done in Turbo Pascal, as opposed to C++ classes.  It seems to me that, ignoring multiple inheritance, you almost have object inheritance with the address operator(:-). Maybe you could simply tweak this operator or the rules by which Maple scopes names to get simple inheritance. 



Thank you. That makes sense. I couldn't find any mention in the help files for creating help.

@Mac Dude 

 No. I assumed that the changes to the help tools package in Maple 2018 might have caused a problem, but I'll give it a try and work through any necessary changes.  Thanks.

Ian McCreath



Thank you.  The type tests you suggested will make my procedure much more robust.

Ian McCreath

@Carl Love

And thus we come back to the basic problem of programming Maple in Windows. I was using the workbook mainly because it provided ready acess to the programming editor which is otherwise only available is the startup code area or the code edit areas of a worksheet. It would have been nice if the editor were available as a standalone application. 

Would you also advise breaking up a large body of code (in excess of 2000 lines) into separate linked modulesto make it more managable?

Thank you.

If my prior posts come across in the wrong way, I apologize. I am frustrated with this workbook problem and having a hard time describing what is going on. My earlier observation was a red-herring. I just noticed that you get two different menus in the Navigator. In one, "attach files" is an unavailable command, in the other "attach files" is available and works.  I thought I had the answer to my problem when I found this, but the real problem remains.

However, I have attached a zipfile of three pdfs of worksheets that illustrate my problem. The file Glyph2.pdf shows how I read my module into the worksheet. Using with to load the module, all of the exports are listed. But after a restart, using the packagetools install command, the modules listed exports do not include all of the exports in the source code, eg. the command DiracMatrices is in the first listing, not the second.

The file Glyph2removerestartcommand.pdf illustrates what happens when I remove the restart command. (I also closed Maple and deleted Glyph2 from my toolbox before I tried the reinstall.) Now Diracmatrices is present in the listing.

However, the file Untitled(2).pdf shows that the module, which is actually available from the toolbox, does not include the new exported procedures.

I really have no idea why  Packagetools seems to reinstall the old package.



@Carl Love 

According to the help topic, "Maple Workbook URI," the Workbook URI (Uniform Resource Identifier) is used to represent the identity and location of files within a Maple workbook or files residing inside another workbook in a given file directory.
A URI  would look like this:
              "exampleURI := "this:///MyCode.mpl""

At this time, I can't attach any files to a maple workbook file on my installation.


1 2 3 Page 2 of 3