In a calculation I am encountering expressions of the following kind:

-.27059805007310*sin(.12+epsilon)+.27059805007310*sqrt(1.-cos(.12+epsilon)^2)

As is known, for epsilon < Pi-0.12, the two terms are equal but opposite in sign and the result should be zero (ok, maybe a few 1E-15 for round-off). But for the heck of it I cannot get Maple to simplify this with the assumption e.g. epsilon < 0.1.

This can probably be simplified by squaring the two terms and then subtracting them, but that can possibly lead to other "interesting" effects and besides is a bit cumbersome.

Has anybody found a good way of  doing this?

Thanks,

M.D.

I should know this, but I don't: Is there a plotting command to plot a list of points, like so:

list:=[[x1,y1],[x2,y2],etc...]; plotlist(list);

(a Vector of points would also be ok)?

There is plots:-pointplot which plots two Vectors (or maybe lists) against each other.

plots:-listplot plots a list against the index. Both are useful commands I employ a lot, but sometimes I'd like to plot pairs as above directly.

Note that I do know how to transform the list of pairs into two lists, or whatever; that is not the issue. I am looking whether there is a command that does this by itself, transparently, before I program myself such a routine because I am too dense with the Maple Help facility.

Thanks,

Mac Dude.

I just got a "new" graphics card, NVIDIA GT630, and was wondering whether the CUDA capabilities are accessible. But no luck:

CUDA:-Enable();

Error, (in CUDA:-Enable) CUDA not supported on the current system (see CUDA,supported_hardware for more information)

The CUDA help page with the example, when run, just shows a host of error messages.

I have OS X 10.11.6, the above mentioned GT630 card with claimed 384 CUDA cores and 2 GB of VRAM; NVIDIA WebDriver 346.03.15f16 for the card (i.e. latest for this OS) and NVIDIA CUDA driver 8.0.90 (again, latest for this OS as far as I can tell). My Maple is 2015.2. All this running on a MacPro 4,1.

I am not having great illusions about the performance I should get (this is not a state-of-the-art card today), but it seems to me this combination should be working with Maple 2015 and not throw an error, shouldn't it? Checking the system extensions: CUDA.kext is loaded and its dependencies are satisfied, so I don't see any problem there.

Am I missing something?

M.D.

I have an integral of a sum

Int(Sum(-(Nb*t-n*t__rev)*exp((1/2)*(L+sqrt(-4*C*L*R^2+L^2))*t/(L*R*C)-(1/2)*(Nb*t-n*t__rev)^2/(Nb^2*sigma__b^2)), n = 0 .. Nb-1), t);

that I want to convert into a sum of integrals since Maple will not integrate the sum but it will integrate the summands. I tried IntegrationTools, but none of these tools seem to do it. It is a part of a larger expression so doing this by hand is not a real option.

Mac Dude.

Following situation: I have a bunch of matrices A,B,Dm, Dinv (which is the inverse of Dm). They happen to be 2x2 matrices, but I want/need to keep these in a symbolic or abstract form, i.e. I am not saying what these are.

They are then used as submatrices of other (2x2) matrices like so:

R:=<<A|0>,<0|B>>;

I then have various dot products between these & others.

My issue/question is: How can I make sure, Maple obeys the non-commutativeness of the products that occur in doing these matrix products? I tried declaring A and B etc. as Matrix(), but that fails, saying the matrices are either too short or too long.

At any rate, I do not want Maple to expand these into their elements. A particular concern is that Dm*B*Dinv bcomes B*Dm*Dinv = B; obviously not correct for matrices B,Dm,Dinv.

So, can Maple handle abstract matrices?

M.D.