pchin

Dr. Paulina Chin

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17 years, 21 days
Maplesoft
Senior Architect
Waterloo, Ontario, Canada

MaplePrimes Activity


These are replies submitted by pchin

Regarding Markiyan's request to look at his related question, I simply replied that the Direct Search package is not maintained by Maplesoft. I'd like to help but am not knowledgeable enough about it to answer his question. I suggested contacting the author of the package if the MaplePrimes community cannot answer the question.

Paulina

 

@Mac Dude It is possible to use the procedure form with procedures taking more than one argument. This can be done by wrapping the procedure in another, as in x->f(5, x) for a procedure f taking 2 parameters. 

However, I do agree with you that uneval quotes can be useful in this situation. Actually, in the video, I didn't quite say that users should avoid uneval quotes, but that they shouldn't use them until they have a pretty good understanding of Maple's evaluation rules. Using uneval quotes can be tricky. When I made the video, I had beginner users in mind, though I find that a surprising number of experienced users occasionally make this error as well. 

To be honest, I didn't even think of discussing procedures with multiple arguments when I made the video ... perhaps that would be good material for a future short video. 

Paulina

This help page describes the problem discussed in the video. It is the one that you'll see if you click on the "cannot determine if this expression is true or false" error message that arises in one of the video's examples.

Markiyan, I will suggest that a link to this page get added to the procedure help page.

@Markiyan Hirnyk Thanks for your comment. I hope you'll also like the more advanced worksheets, which I hope to post in the next couple of weeks.

The rules for the Scrabble game can be found at the Hasbro Web site. I didn't include much information about Scrabble in my worksheet because the quiz can be used for other word games too, though the two-letter-word list is of particular interest to Scrabble players. There are other word games, including a number of online ones, that rely on the same dictionary used by Scrabble players in Canada, US and Thailand. This is the Official Club and Tournament Word List, Second Edition, also known as OWL2. The rest of the Scrabble-playing world uses the SOWPODS dictionary. It is easy enough to edit the start-up code in the worksheet to change the two-letter-word list if you wish to use a different dictionary.

Paulina

Hi Axel,

Unfortunately, the worksheet won't work in Maple 12, as I use some new components introduced in Maple 14. The worksheet works correctly in Maple 15 and 16. If you have Maple 14, you'll get an error because the worksheet uses new colours introduced in Maple 15. To fix this, just go into the startup code and change the colours that start with "Niagara" to the colours of your choice.

Paulina

The problem with ranges having more than 3 dots that acer and Joe had commented on is indeed a bug and it's already in our database.

Paulina

It does indeed look like a bug in the display of the Logic package's operators. I've added this report to our bugs database and we'll look into it.

Paulina

It does indeed look like a bug in the display of the Logic package's operators. I've added this report to our bugs database and we'll look into it.

Paulina

We are looking at various ways to make it easier for users to specify Pi tickmarks. Having them generated automatically is one possibility but we are also seeing if we can make improvements to context menus and the Plot Builder. There are some challenges associated with having automatic tickmarks, including how to merge plots with conflicting options. I don't want to get into the details here and I can't promise when/if improvements will appear in future releases, but this feature has been requested in the past and it is under consideration.

Paulina

The reason why the 2-d procedure takes longer is because the 2-d dot operator has a broader scope than the 1-d dot operator. The dot operator is used to represent a number of different operations, including vector calculus operations. At parse time, it is not always possible to tell which meaning is the intended one. Thus, the 2-d dot operator translates into a procedure that examines the arguments after they are passed in and, using the types of the arguments, deduces which of the various "dot" commands is appropriate.

In my own Maple use, I like 2-d math for entering complicated math expressions and to get input and output that looks like math. However, for programming purposes, I tend to use 1-d math input because within procedures, context information that's useful for parsing isn't available until the procedure is called. For writing complicated procedures, especially when efficiency is very important, I suggest using 1-d input.

I will add, though, that we are aware of the issues related to the 2-d dot operator that have been brought up on MaplePrimes, and we do have long-term plans to improve this situation.

Paulina

I can confirm that the plot command is not reentrant. You can't pass a procedure to the plot command that itself calls the plot command.

Paulina

I can confirm that the plot command is not reentrant. You can't pass a procedure to the plot command that itself calls the plot command.

Paulina

@Christopher2222 The earliest release containing this fix would probably be the next full release, though there is a possiiblity it may be put into a dot release.

Paulina

@Christopher2222 The earliest release containing this fix would probably be the next full release, though there is a possiiblity it may be put into a dot release.

Paulina

@stefanv Thanks for the historical info, Stefan, and confirming that the plot code has its silver anniversary next year. I remember talking to some of the students working on Maple back in the mid-80s at U of Waterloo. A very enthusiastic bunch they were.

Paulina

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