GeorgeJ

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18 years, 36 days

MaplePrimes Activity


These are answers submitted by GeorgeJ

I’m not sure what the problem is. I just copied your code into both MAPLE10 and MAPLE 11 and in both cases got 6 8 10 12 14 Here’s my worksheet for MAPLE10. View 2292_DoLoop.mw on MapleNet or Download 2292_DoLoop.mw
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David, Thank you for pointing out the proof using features in the Logic package. I notice that in that package you have to put ampersands in front of the operators. I was wondering if it is possible to prove de Morgan's just using the MAPLE operators and or and not without the ampersands. I did it but my proof was cumbersome using truth Matrices. I was wondering if there is a more compact way. I suspect that there is one which uses 'implies' but I still can't figure out how to use that command.
At the end of chapter 3 in the Introductory Programming Guide problem 7. asks "Use MAPLE to verify de Morgan's laws." I was able to do this but am afraid my presentation which involved creating and comparing two 2x2 matrices was unnecessarily cumbersome. I have the feeling that it would be possible to prove these laws using the "implies" command. Unfortunately, althought I did find mention of the existence of this command I have not been able to find an example of its use. Could some one show me an example of how this command is used. Could it be used to in the proof of de Morgan's Laws?
Thanks very much. That works. I am having trouble using that function with either the ‘use’ or ‘with’ syntax. I keep getting errors. Could someone show me how to use `:-Equal` in a command in which it was not immedeately preceeded by `LinearAlgebra`. This doesn’t work With LinearAlgebra :-Equal(A,B)
{I am wondering why you should want to put a dot above a hat (circumflex). J. Tarr} What if you want a compact way to indicate the time derivative of a unit vector? Sure, there are other ways of displaying that, but I have seen dot-over-circumflex used in certain presentations on WIKIPEDIA and it seems to be a worthwhile method. I was just wondering if there is any way to accomplish that in MAPLE. Well, I'm off to investigate MathML (thank you Alex) and if I find anything useful regarding dot-over-circumflex I'll post it in case anyone is interested.
Thanks very much. That thread was most helpful. I'm still digesting it.
I completely agree w your statement that absolute backwards compatibility is the death of progress. Ignoring the trivial solution is probably a good idea. I was just wondering if there was perhaps some switch I had inadvertantly set in M11 which caused this solution to be ignored. I guess not. No big deal. Here’s a completely different question: Is there any way in MAPLE to put a hat, ^ , on top of a variable. I’ve been using the underscore, e. g. the unit vector in the r direction is r_, whereas ‘r hat’ would be more appropriate. The problem I’m running into is that in the printed (as opposed to screen) version of my paper, if r_ is in the denominator of a fraction, the underscore is hidden by the fraction bar. Also, what about dots on top of a variable a la Issac Newton? -regards
Every time I think I'm making some progress in understanding the MAPLE paradigm, a helpful person on this forum shows me a much better way of doing something and I feel like a complete beginner again :). BTW, does your 'InitializeArray', which is obviously vastly superior to my own, also suffer from the problem that 81 versions of the sumbols 'Number', 'Possible' and 'NumPossible' must be stored in MAPLE's symbol table at run time? -regards
I just received MAPLE11. Introductory Programming Guide and Advenced Programming Guide appear identical to those of MAPLE10. I haven't checked every page but selected ramdon pages are identical. Well, as I said in my previous post, I'll read through the entire trio before I commence more whining about MAPLE's documentation :).
Thomas, it seems others on this forum agree w me to some extent about the documentation. I did find the section you referred to in the Introductory Programming Guide. I guess I should have looked there. Since I didn't find it under 'Array' in the Users Guide I stopped looking. I do think a case could be made that it would have been more appropriate to put it in the User Manual, as its not necessarily a programming issue. But I take your point. I'm due to receive MAPLE11 any day now and have resolved to read all the manuals from beginning to end as soon as practical. Also, if the disk includes pdf files of the manuals I will take your suggestion and do searches on these files.
Clearly it would be impractical to document in hard copy all of the important features of MAPLE. What I would strongly recommend is that someone at MAPLE spend a fair amount of time and effort considering MAPLE from the standpoint of a new user. This person should try to figure out what is the really important stuff that a user should know, and put this information in what I would call the "learning documentation". This documentation would not necessarily be hard-copy. I would certainly include 'copy' in this category of important stuff to know. I would never have known about 'copy' if it were not for Joe's post. 'copy' is an extremely important command insamuch as the assignment a:=b is fundamentally different in the case of b being a structured variable from the case in which b is not a structured variable. I don't think this fact is made clear in the documentation. In any event, I do hope that some folks from MAPLE are reading this thread and that they will consider in the next iteration of MAPLE including in the learning documentation some discussion of 'copy', as well as of the fundamental difference of an assignment statement when the rhs is a structured variable as oppposed to when it is not. Once again, I say thank God for MAPLEPRIMES!
Bonjour Xavier, I don't speak French well but I understood your post. A while ago I wrote a Sudoku solver in Visual Basic, and am in the process of translating it into MAPLE. I would very much like to see your program, but I want to finish mine first. You may be hearing from me in a few weeks. In the mean time you might want to consider uploading your program. Merci
I looked up copy in the indices of the 3 books which came w/ MAPLE10 and the only reference was to copy and paste. I hope that in MAPLE11 they think to include this extremely useful command in the printed documentation. Since I didn't know of the commands existence I didn't know to type ?copy.
Thanks Joe, that's really helpful.
I'd like to thank all of the above for helping me in this matter. I did not know that MAPLE handled lists differently from vectors. In the situation in which I was having the problem I took the suggestion used a vector instead of a list and the problem went away. I'm still having trouble getting my mind around what might be called the MAPLE paradigm. My mind is still operating in the mode of VB and C++. In those environments, you first declare a variable and then put values into it. Evidently in MAPLE, it would be helpful in many cases to think of in terms of 'symbols' rather than 'variables'. Look at this.. > Vector1 := (Vector[row])(5, [1, 2, 3, 4, 5]); [1,2,3,4,5] > Vector2 := Vector1: Vector2 [1,2,3,4,5] > Vector3 := (Vector[row])(5, [seq(Vector1[i], i = 1 .. 5)]); [1,2,3,4,5] > Vector1[5] := 100: Vector2; [1,2,3,4,100] > Vector3 [1,2,3,4,5] I imagine lots of people who are used to traditional programming languanges would not have expected Vector2 to be changed by a change to Vector1. I have to keep reminding myself that Vector2 is just a symbol to a variable - its not itself a variable. Question - if I want to create a new Vector3 which initially has the same values as Vector1, is there a less cumbersome way to do it than the way I did it here? -thanks in advance
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