For those who might not know about Blokus, it's a puzzle game for 2 to 4 players. Very easy to learn to play, and fun for groups of different ages and knowledge levels (in my opinion, as one who loses with regularity to my 9-year old son).

The official website is http://www.blokus.com/ .

It's not immediately clear to me exactly what the OP has in mind. Does he expect an interface that provides an interactive interface? or a smart system that tries to play with some sophistication? or something else? There are many different variations of Blokus, including a 3d Blokus, so you might want to be more specific as to exactly what you have in mind.

I believe there are electronic versions of Blokus for some of the video game systems, and an online version from the above website.

Doug

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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

I cannot access the worksheet.

Clicking on the link in the message opens a blank tab/window in the browser.

Saving the file to my desktop gives a file of 0 bytes.

Can you repost the worksheet, or copy the equations to the body of your post?

Doug

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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

Just saw this. I will try to relocate this file - later this afternoon.

As I recall, I never did find a 100% satisfactory solution. Maybe someone else will have some better ideas now.

More later,

Doug

First, you should not be using matrix or the linalg package. The Matrix structures and the LinearAlgebra package are much more robust.

What are you hoping to get from this? I doubt you'll be able to see an explicit inverse for a truly general matrix.

Here's how I would get started:

with( LinearAlgebra ):
A11 := Matrix( n1,n1 ):
A12 := Matrix( n1,n2 ):
A21 := Matrix( n2,n1 ):
A22 := Matrix( n2,n2 ):
A_big := < < A11 | A12 >, < A21 | A22 > >:
MatrixInverse( A_big );

You should look at the online help for ?LinearAlgebra/VectorAngle for some examples.

Doug

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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

You mention that you have a good start on your problem, but would like help finishing it. If you would share with us what you have done so far, it would make it much easier for one of us to show you how to take the next steps.

If I start from scratch, I might do things completely different than you, and my solution would not be as helpful to you as if I could see your current work.

Posting a complete worksheet is probably the easiest way for you to share what you've done so far.

Looking forward to working on this one,

Doug

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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

I see that I earned 2 badges today, but am not yet familiar enough with them to know which 2 have been earned today.

Maybe the badge information could list the date on which a badge was earned?

Doug

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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

Oh, that makes sense. But, is it explained on that page? Still, the arrangment in columns would make this clearer.

The badges section of the profile could be improved. The default view is fine. It would be nice to be able see all of the badges, or at least the ones toward which I have earned partial fulfillment. Not that earning badges is the reason to contribute to MaplePrimes, but it could encourage users to make use of certain features (e.g., including links to help pages - one that I'm disappointed I do not already have as I know I've included lots of links to help pages over the years.)

Also, when I saw your comment, it says my post was made 4 hours ago, but it's really been less than an hour. I have not looked at other posts in enough detail to try to figure out the problem - time zone, .... I'll let you handle this.

Doug

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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

The University of South Carolina received its distribution of Maple 14 in the middle of May. We are in the proces of installing it on our lab computers for use in Fall 2010.

When I was looking at the Maple websites, I did find comments that complimentary copies of Maple 14 would be sent to the beta testers who had contributed the most to the testing of the software. This might be a change from previous editions, but they are being very clear about this (while the specific quantification of "contributions" is not very specific).

Doug

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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

Ignore the if statement (for now). The rest of the procedure is just a wrapper that combines 2 calls to the numeric solution, and returns either one component of the solution (X or Y) or a list of both components (XY) for the given value of t.

If you omit the if statement from the definition of, say, X:

X := proc(T,H)
  global integ;
  integ(parameters=[H]);
  eval( x(t), integ(T) );
end proc:
X(1,2);
                             1.00277830286020797

Now, look at the outputs of this procedure when one or both of the arguments is not a number:

X(1,t);
Error, (in dsolve/numeric/process_parameters) 'parameters' must be specified as a list of numeric values or equations of the form <parameter>=<value>
X(a,2);
Error, (in X) invalid input: eval received integ(a), which is not valid for its 2nd argument, eqns
X(h,t);
Error, (in dsolve/numeric/process_parameters) 'parameters' must be specified as a list of numeric values or equations of the form <parameter>=<value>

These errors arise because the numeric solution, integ, does not know what to do if the parameter value or the independent variable is not explicitly numeric.

To understand what the if statement does, and its use of procname and args, see the online help for procname ( ?procname ).

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

Ignore the if statement (for now). The rest of the procedure is just a wrapper that combines 2 calls to the numeric solution, and returns either one component of the solution (X or Y) or a list of both components (XY) for the given value of t.

If you omit the if statement from the definition of, say, X:

X := proc(T,H)
  global integ;
  integ(parameters=[H]);
  eval( x(t), integ(T) );
end proc:
X(1,2);
                             1.00277830286020797

Now, look at the outputs of this procedure when one or both of the arguments is not a number:

X(1,t);
Error, (in dsolve/numeric/process_parameters) 'parameters' must be specified as a list of numeric values or equations of the form <parameter>=<value>
X(a,2);
Error, (in X) invalid input: eval received integ(a), which is not valid for its 2nd argument, eqns
X(h,t);
Error, (in dsolve/numeric/process_parameters) 'parameters' must be specified as a list of numeric values or equations of the form <parameter>=<value>

These errors arise because the numeric solution, integ, does not know what to do if the parameter value or the independent variable is not explicitly numeric.

To understand what the if statement does, and its use of procname and args, see the online help for procname ( ?procname ).

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

You write that this is your "thesis subject". This sounds interesting. In most cases, the point of a thesis is the process of doing the work on this subject. Regardless of the topic involved, you start with a simpler problem and build up to the problem of interest to you.

It's already clear there are many on this site who could give you some nearly complete solutions to your problem, this is not the goal of your thesis.

• What, besides posting on MaplePrimes, have you done to get started on this?
• What else do you know about Maple?

Before you even try to work on this problem, you should learn how to do basic plots and how to work with differential equations in Maple. There are lots of examples in the online help, and this board can be a valuable resource - but don't ask us to do all of your work for you. Here are some specific questions you should work to understand as you get started.

• Do you know how to enter an ODE and work with general solutions or solutions to an IVP?
• Do you know how to do this with explicit solutions, and with numeric solutions?
  Which are you going to be working with for your problem? (Do you know?)
• Can you plot the solution as a 3d surface?
• Can you plot the solution for a specific instant of time?
• Can you create an animation of a slice moving through another surface?
  For example, create a plot of the surface z=sin(x^2+t^2) on a reasonable domain.
  Then, plot the cross section of this surface for a specific value of t, say t=0, or t=1.

If you can show that you understand how to do these, then I think we can help you move towards understanding your thesis problem.

Your thesis advisor should be having you work through these steps. If not, then I hope you will accept this response as a assistance and do the work so that  you can better understand your problem and ultimately come to your own solution to the problem.

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

You write that this is your "thesis subject". This sounds interesting. In most cases, the point of a thesis is the process of doing the work on this subject. Regardless of the topic involved, you start with a simpler problem and build up to the problem of interest to you.

It's already clear there are many on this site who could give you some nearly complete solutions to your problem, this is not the goal of your thesis.

• What, besides posting on MaplePrimes, have you done to get started on this?
• What else do you know about Maple?

Before you even try to work on this problem, you should learn how to do basic plots and how to work with differential equations in Maple. There are lots of examples in the online help, and this board can be a valuable resource - but don't ask us to do all of your work for you. Here are some specific questions you should work to understand as you get started.

• Do you know how to enter an ODE and work with general solutions or solutions to an IVP?
• Do you know how to do this with explicit solutions, and with numeric solutions?
  Which are you going to be working with for your problem? (Do you know?)
• Can you plot the solution as a 3d surface?
• Can you plot the solution for a specific instant of time?
• Can you create an animation of a slice moving through another surface?
  For example, create a plot of the surface z=sin(x^2+t^2) on a reasonable domain.
  Then, plot the cross section of this surface for a specific value of t, say t=0, or t=1.

If you can show that you understand how to do these, then I think we can help you move towards understanding your thesis problem.

Your thesis advisor should be having you work through these steps. If not, then I hope you will accept this response as a assistance and do the work so that  you can better understand your problem and ultimately come to your own solution to the problem.

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

Is there any hint as to when we will actually be able to get our hands on the released version of Maple 14?

If we are going to migrate to Maple 14 for the 2010-2011 academic year, I need to be able to give it to the lab coordinators in time for them to update our materials over the summer - and for our campus to get the new version installed across campus.

Doug

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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

Based on a quick read, the most noteworthy improvement that I see is

Plotting Enhancements
Tools for creating and exploring 2-D plots have been enhanced.

• Improved plotting of 2-D functions with discontinuities lets you highlight removable discontinuities and offers greater control over the appearance of plots.
• The enhanced point probe tool lets you explore the coordinates of a 2-D plot. In addition to displaying the current cursor location, the point probe can find the point on the curve closest to your cursor, or even the closest point that Maple calculated to produce the plot. It also lets you extract the coordinates of the cursor and paste them anywhere in the document, in the form of a valid Maple object.

It's been more than 10 years that I, and many others, have been asking for the ability to get the coordinates from the "point probe" into the Maple worksheet. Maybe it's just my personal bias, but I'd have given this a more prominent placement - certainly not the last sentence in this section.

Both of these improvements have the potential to get heavy use in our Calculus labs. A final decision on this will have to wait until we actually see how they work in Maple 14.

Doug

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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

As Preben showed, this functionality has always existed within Maple. In addition to being more efficient, as pagan shows, I find the new syntax more natural.

The event handler is also nice. It does appear to have some limitations - the topic of a future post.

I find the timing of these enhancements and the appearance of MapleSim more than pure coincidence. It's my guess that MapleSim makes heavy use of numeric dsolve. If only I had more time to explore this.

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