Mac Dude

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These are questions asked by Mac Dude

Following situation: I have a bunch of matrices A,B,Dm, Dinv (which is the inverse of Dm). They happen to be 2x2 matrices, but I want/need to keep these in a symbolic or abstract form, i.e. I am not saying what these are.

They are then used as submatrices of other (2x2) matrices like so:

R:=<<A|0>,<0|B>>;

I then have various dot products between these & others.

My issue/question is: How can I make sure, Maple obeys the non-commutativeness of the products that occur in doing these matrix products? I tried declaring A and B etc. as Matrix(), but that fails, saying the matrices are either too short or too long.

At any rate, I do not want Maple to expand these into their elements. A particular concern is that Dm*B*Dinv bcomes B*Dm*Dinv = B; obviously not correct for matrices B,Dm,Dinv.

So, can Maple handle abstract matrices?

M.D.

In answer to a previous question (https://www.mapleprimes.com/questions/228965-How-Can-I-Save-A-Record) acer introduced me to the .mla archives as a possible store location for variables.

I have been working with this and now end up having 4 .mla files (called results1.mla...results4.mla) that each hold output from some lengthy batch running of maple. Each of these has two tables with values called Beams and Beams2 (same name in each of these archives). While named the same the content is different.

My question is: How do I get at each of these? As acer explained, the content (i.e. the tables Beams and Beams2) is mapped into the namespace of the Maple session once libname includes the directory where the .mla files sit. They are actually in the same directory as the associated Maple programs so they mask each other.

I tried to juggle libname prepending the .mla file I want to the rest; but that does not seem to work (I always get the same data). I do need the data all in one worksheet for collating and postprocessing and display.

TIA,

M.D.

I have a relatively involved modeling application that tracks  a particle beam through a beam line for multiple passes. The beam is described by a Maple Record with a number of different entries; one of them being a table with a 6-vector of numbers for each particle in the beam.

Each pass this beam gets updated. I would like to be able to save the whole record into a filel (i.e. append the file each pass) and then be able to read it back in; regenerating the Record structures. Is this possible?

(I'd normally upload a mwe; except this code uses a large package that would have to be installed. This is something I do not consider reasonable to ask for.)

If there is an explicit answer like: call this function, give it your Record and it should work; and call this reading function to recreate the Record, that would be swell. Or maybe some pointers in the right direction...Maple has so many read, write, save and restore functions that a systematic test is daunting.

TIA,

Mac Dude

I have a .mapleinit file that amongst other things sets libname so my own packages are accessible and can be loaded using with(). Imagine my surprise when I found that a maple program that ran half an hour ago on Maple2019 bombed when it did not find its package. Closer investigation indicates that maybe .mapleinit is only searched for in currentdir()??

The updated Maple is `Maple 2019.2, APPLE UNIVERSAL OSX, Oct 30 2019, Build ID 1430966`

The old one is gone :-(. It was Maple2019.0. I should add that on this system, Maple is installed on an administrator account that is not my user account (luckily I have access to that). I am running macOS 10.14.6 Mojave.

I verified my older Maples still work as before.

Has anyone else seen this behaviour?

Mac Dude.

Edit: I need to be more specific here: When I double-click a worksheet (.mw file) then currentdir() will be set to the directory the .mw file is in. This has been long-standing Maple behaviour. But then currentdir() does not cover the home directory where .mapleinit sits. As a result, a blank sheet finds my .mapleinit whereas my files (that habitually I open with double-click or drag-drop) do no longer run the .mapleinit file.

 

I have a simple plot showing a quantity against another. The vertical axis values happen to be relatively large integers (tuning words for a direct digital synthesizer, if anyone cares). In the plot pasted-in below this would be W. Maple insists plotting these in scientific notation with 5 or so digits. Is there any way to force the vertical axis to show labels in integers? I scoured the docs for this but came up empty. To be clear, Maple does the right thing in 99% of all cases, is just that these tuning words are integers so the scientific expression makes no sense here. Plotting the equivalent Hex value would also be acceptable, except that I don't know how to do that either.

Thanks,

Mac Dude

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