What do you mean by "do this is by using the Tabulate (plain command and not from DocumentTools) function"? As far as I can tell, there is no "plain" top-level Tabulate, only Tabulate commands in packages DataFrame, DocumentTools, and StringTools. Are you converting a Matrix to a DataFrame before using Tabulate?

I have had that bug on my computer before (many times), but I haven't seen any reasonable explanation for it, nor can I reproduce it. It doesn't seem to be widely reported. It is intermittent. When it's happened to me, other symbols also change, such as + and - becoming C and K. Does that happen for you? And when it happens to one of my worksheets, all open worksheets are affected. If I save my worksheets and close the entire Maple session, the bug is gone when I restart Maple---the errors are not stored in the saved worksheets.

@Mike Mc Dermott If I made a suggestion in this thread, it seems to have disappeared. I recall thinking about a suggestion for this thread. What is the thing that you think is "even better"?

@JAMET Using that code, I do get [4, 18/5, 1].

@Rouben Rostamian The YouTube video that you linked is an excellent demonstration and explanation of the motion of balls on rotating platters. And it explains why certain patterns can be explained entirely by the moments of inertia.

If there's no friction, then why would the carousel have any effect at all on the cube, regardless of whether or not it's self-propelled?

I think that using the principles from, say, a first university physics-for-majors course, the only approach to the problem is for it to be a round object (cylinder or sphere, solid or hollow) rolling without slipping. The moment of inertia of the object comes into play, which can be easily calculated for spheres and cylinders (uniform solid or hollow).

Do you intend for &x to represent the vector cross product of two 3-D vectors? That's what &x usually means in Maple. Or do you want the product of a Matrix, the inverse of Mat, with a vector?

@mmcdara I think that the answer to both of your most-recent questions is that the Statistics package was written before Maple formally had objects, and RandomVariable would greatly benefit from having its code refactored as an object.

@FDS I tested the 3rd line of code from my Answer in 2D Input, and it works. Here it is applied to row selection:

Download select.mw

@Laurenso A warning is not an error. After receiving the above warnings you can proceed to run the procedure. The warning can be avoided by putting local j, k; in the locals area of the procedure.

Please repost the Question (by editing this Question). If someone thinks it's a duplicate, they ahould post some evidence of that, such as a link. Anyway, I think it was a great Question.

I hate all such meta-tags, I never use them, and I wish that they were forbidden! If a Moderator is sure that something is a duplicate, they should delete it. Anything less is sniveling passive aggression.

I don't recall ever seeing a duplicate to your original Question.

I don't understand what mathematical principle allows you to discard exp(x^2) as being "not real". Perhaps you want to discard it because it can't be 0? That's a separate issue. If that's what you mean, let me know.

While it's true that real is not a Maple type, it is a Maple property, and properties are the primary modality of assuming.

@emendes Change

nops(convert(Models_4,set));

to

nops({op~(Models_4)[]});
                              1170

@mmcdara 

 I didn't mention this before because you use Maple 2015 (at home), which I don't think supports embedded do loops. But for completeness and for when you're not at home, these are IMO the best replacementas for your loop:

L1L2:= [while not T['finished'] do T['nextvalue']() od]:

or if you know that the Cartesian product is nonempty

L1L2:= [do T['nextvalue']() until T['finished']() od]:

or if you know that it has n elements

L1L2:= [to n do T['nextvalue']() od]: