@reza_maple For C+Z.C^(-1).X=D you might be able to use LinearAlgebra:-CARE available in Maple 14.

The substitutions would be something like [X=C,R=X, A=D.X^(-1)/2, B=IdentityMatrix, S=ZeroMatrix, Q=-Z].

This could presume that each of (your) D, C, and X are symmetric.

@reza_maple For C+Z.C^(-1).X=D you might be able to use LinearAlgebra:-CARE available in Maple 14.

The substitutions would be something like [X=C,R=X, A=D.X^(-1)/2, B=IdentityMatrix, S=ZeroMatrix, Q=-Z].

This could presume that each of (your) D, C, and X are symmetric.

In the sample code that you posted, you assigned values to the first column of Matrix vel, ie, to vel[1,1],vel[2,1], and  vel[3,1].

But your code didn't assign values to the other columns of vel. Note that the updating code uses vel[1,i], vel[2,i], vel[3,i] for values of i other than 1. So, if vel is a Matrix, those further columns' entries might each have the default value of 0.

Could that be part of it?

In the sample code that you posted, you assigned values to the first column of Matrix vel, ie, to vel[1,1],vel[2,1], and  vel[3,1].

But your code didn't assign values to the other columns of vel. Note that the updating code uses vel[1,i], vel[2,i], vel[3,i] for values of i other than 1. So, if vel is a Matrix, those further columns' entries might each have the default value of 0.

Could that be part of it?

@JacquesC I'm not disagreeing with you, but is it relevant that there was a corporate blog item on step-by-step tutors and tools posted on May 12, 2010? It's currently linked from Mapleprime's front page (in the right panel).

ps. If I recall, I came across this one while fiddling with this problem on usenet.

Are you suggesting showing only the combined tally of +1 and -1 votes, and not also showing the plus-tally and minus-tally? Perhaps I musunderstand, and you are only talking about layout, or about the introduction of a combined tally while retaining the other pair?

For example

Up 4

-2

Down 6

I like being able to tell the difference between scenario A in which there are several people with opposing views and scenario B in which nobody cares about the post enough to rate it. I think that it's a very useful distinction, which of course would be lost if only a combined tally showed.

I think that most people can do the addition of (Up - Down) for themselves, no?

BTW, both up-votes and down-votes currently affect reputation (and the weighting of those effects could be adjusted), so there seems no need for a post's combined tally/score to also affect it.

When I first read this post a day or so ago, I thought to myself, "ha! easy, just use parameters & dsolve/numeric!". Then I saw that the ics[i] changed depending on the symbolic solution at each i, and my heart sank since that seemed to precluce a nice solution using purely numeric parameters. Now it looks as if Erik has seen what I was blind to. Hopefully I can learn a lesson here. Way to go, Erik.

When I first read this post a day or so ago, I thought to myself, "ha! easy, just use parameters & dsolve/numeric!". Then I saw that the ics[i] changed depending on the symbolic solution at each i, and my heart sank since that seemed to precluce a nice solution using purely numeric parameters. Now it looks as if Erik has seen what I was blind to. Hopefully I can learn a lesson here. Way to go, Erik.

@Will 

Yes, I can easily provide such examples. I hope that others do as well, because it seems like a fundamental use of tags.

For example, "efficiency & maplesim" (so that it doesn't just hide any returned results in the many hits for product Maple proper.)

For example, "integration & exact" or "integration & numeric".

I hope that it shouldn't be necessary to point out the a regular Search is not going to suffice. One of the points of tags is that using them can dramatically reduce the noise of a regular search.

@hirnyk Being able to automate such tasks is important. Compare with the various questions about automatically writing a sequence of plots out to files, for example.

@hirnyk Being able to automate such tasks is important. Compare with the various questions about automatically writing a sequence of plots out to files, for example.

@Alec Mihailovs You made a claim that only 5 members currently had thumbs down badges, as shown here.

But it does not follow logically that those 5 members are only those responsible for all current thumbs down marks on posts. The reason for this is that badges are not currently being updated (as you yourself pointed out in a post).

They might be responsible, of course, but it doesn't follow necessarily, on account of the badge-updating-delay.

@Christopher2222 That's an interesting idea. Short qualifiers on down votes. What could be in such a set of qualifying comments? How about {"inefficient: memory", "inefficient: speed", "answers another question", "doesn't work as claimed", "disagree (opinion)"} and so on.

And why not something similar for up-votes too? It would avoid clutter of short replies stating any of those things (which happens...)

The Application Center would gain credibility if its classification of submissions were more accurate.

Look at the section named Complex Analysis. There are some embarrassingly wrong placements there. It's almost as if someone thought that "complex analysis" meant "complicated investigation" instead of being the technical name of a math subdiscipline.

@Christopher2222 Not all of the old book pages are now missing. I've seen many that were imported just fine. But this "tine" one looks empty.

It's probably wrong behaviour that the mapleprimes search engine i still returning results to the old, removed versions. I mean, the ones that have urls like "http://www.mapleprimes.com/book/export/html/4473" when in fact the new version is only at "http://www.mapleprimes.com/posts/40175-The-Top-Ten-Maple-Errors". The search engine shouldn't be reporting any such defunct pages like ".../book/export/html/..." which are likely just temp artefacts from the move.