@karishma I applied two days ago (shortly after Alec Mihailovs made me aware of the program) and now awaits a reply from MapleSoft.

@Nick Using lists, it is not necessary to fix any length, say 120. You can start with a list with one element, a Vector, say:

velocities := [Vector([1,2,3])];

Then you can augment the list with new elements as follows (the example here given amounts to that formerly given):

velocities := [velocities[],Vector([2,3,4])];
velocities := [velocities[],Vector([4,3,2])];
# etc.

The elements can be accessed as follows (applies also if a list of lists had been used):

# The z-component of the second velocity data point
velocities[2][3];

PS: Your reservation towards using an ordered data structure puzzles me a bit: it seems to me that the opposite, i.e., an unordered data structure (a set, for instance) would make it impossible to keep track of the data points along the trajectory of the baseball.

@Nick Using lists, it is not necessary to fix any length, say 120. You can start with a list with one element, a Vector, say:

velocities := [Vector([1,2,3])];

Then you can augment the list with new elements as follows (the example here given amounts to that formerly given):

velocities := [velocities[],Vector([2,3,4])];
velocities := [velocities[],Vector([4,3,2])];
# etc.

The elements can be accessed as follows (applies also if a list of lists had been used):

# The z-component of the second velocity data point
velocities[2][3];

PS: Your reservation towards using an ordered data structure puzzles me a bit: it seems to me that the opposite, i.e., an unordered data structure (a set, for instance) would make it impossible to keep track of the data points along the trajectory of the baseball.

@Joe Riel and Christopher2222: So the status now seems to be that Maple 12 most probably is a no-go, whereas Maple 13+ is a go.

@Joe Riel Thanks for trying that out. Just to be sure, is it the code given here?

@Alec Mihailovs Thanks for suggesting that interesting option.

I have just read the FAQ-page on beta-testing, and I'm inclined to sign up. In view of my above critical post (what you refer to as 'free speach'), the question, of course, is whether MapleSoft will accept me as a beta tester.

Thanks Christopher2222 for your valuable comment.

It makes it possible for me to conclude that there is no point for me in buying Maple 12+ as that would not remedy the 'tabbing-nuisance' I experienced after having bought Maple 11 a couple of years ago. I will just stay with my current properly working version, Maple 9.5.

I must say that MapleSoft's missing action on this, may I say fundamental, matter both amazes and disappoints me. I would appreciate from them, at the very least, an explanation as to why they do not, or cannot, fix this problem.

I assume, then, that the heavily loading of XML in Maple documents, introduced with Maple 11, is still with us!? If that is affirmative, then, for me, that is another reason for not going Maple 12+.

Thanks for clearing that up.

Thanks for clearing that up.

As a newcomer to this interface, I wonder why the above post of mine figures on top of posts given priorly by others? It does not seem to be due to reverse chronological ordering; so what then?

As a newcomer to this interface, I wonder why the above post of mine figures on top of posts given priorly by others? It does not seem to be due to reverse chronological ordering; so what then?

"Nice tto see John again.": Thanks!

"Nice tto see John again.": Thanks!

It does not work for me either, and it has not worked since the mapleprimes "update" which, it seems, was more concerned with cosmestics than usability. See for instance The pre, code, and maple tags and Maple tag, still ....

Maybe the wikipedia page General relativity may also have your interest. As to the golden road towards general relativity, I am not sure. I think that it depends on ones background, for instance, whether you are a mathematician or a physicist, or something third.

Back in the late eighties I struggled for three years on my own [at that time no formal course was available at my university, believe it or not] before I understood general relativity. The difficulty was, along side understanding the intimidating machinary of tensor calculus, to give up my physical notion that coordinates matter - they don't: coordinates are only the work of man. The coordinate covariance of the equations of general relativity embodies that notion.

So, to me there seems to be two things to understand: the tensor calculus of Riemannian manifolds, and the physical reason for using it in the description of gravitation. Doing the former without the latter gives a very valuable insight into the beautiful concepts of Riemannian geometry [geodesics, connection, curvature, etc.], but does not necessarily give one an understanding of gravitation and the true genius of Einstein.