I have written a Maple code which extracts terms in a matrix into two new matrices dependent on certain markers. I am running into problems with this particular code as it requires enormous amounts of RAM when going to large matrix sizes (32GB+); and will take 4-5 days to complete for larger matrix sizes, or simply crashes.

Each matrix element is an algebraic expression containing A and B and the markers hh and ss. The example in the attached Maple file (3 x 3 matrix) is a minimal working example and the actual expressions are much longer and the matrices much larger (5000 x 5000 or larger). I utilise the symmetry of the matrix to ease the process, and use the tril command of MTM to extract only the lower triangular matrix; as this is all that is needed for the next stage (I have yet to test how efficient this command is, but use it for now).

The two markers hh and ss are targeted and if found in an expression that term will be extracted accordingly. The matrix elements are expanded and a procedure run over the matrix and will extract terms with hh into one matrix and terms with ss into another matrix. I think the map(expand,...) part is what causes the memory issue; but I believe this needs to be done to correctly extract terms.

Any help or tips are greatly appreciated on how to increase efficiency and improve this method.
 

Sub_matrix_extraction.mw

-Yeti

I did dummy indices implication using add command as below. is it OK or there are mistakes?

Is there another way to imply dummy index summation in maple instead of using add command?

any suggestion???

Download Mesal.mw

 ODE:= -2 sin(1/2 theta(t)) cos(1/2 theta(t)) (diff(theta(t),t)^2-9.8000 sin(theta(t))-(150+4 sin(1/2 theta(t))^2) (diff(theta(t),t,t)=0:

 ICS:=  theta(0) = Pi/6, D(theta)(0) = DthetaZero:

Hi, i wonder if there is a way to solve this 20×20 equations system for maple. Im trying fsolve but it doesn't work. aceitoso
 

Download aceitoso.mw

Is any package or algorithm which enable me to compute constraint structure of a singular Lagrangian in physical phenomena?

i would be very thankfull if someone help me in thisway please :)

I recently changed to a very high resolution monitor. The worksheet material is fine, since I can control the  zoom level, but the material at the top panel, the menus and information in the help page panels is much too small,  How can it be controlled?

Thank you,                        --Micha Hofri

Comment:   The responder tomleslie indeed identified the problem --- fixed pixel-count programming  Some software products, such as the FireFox browser provide access to hundreds of configuration parameters.  Surely the Maple tools have such a file, but I have seen no access.

The monitor I use is indeed of high resolution, the manufacturer says it is 3840x2160, (24'' -- I use 2 of them in a T configuration).  It is a delight, except when trying to read minute characters.

I suppose I need a pointer from the people in the know........Micha Hofri

Responding to a comment by Mac Dude that the issue may have to do with Windows.  I assume he refers to the MIcroSoft OS.

My computers run the Mint distribution of linux (window manager is Mate).  These matters are important, yet my needs would likely be addressed by the Maple user interface mechanisms.

My difficulty is finding a way to interact with these mechanisms, I suppose.   --Micha Hofri

The worksheet below shows a river whose velocity is a function of the distance from its mid point to either bank.

In this worksheet, as an example, a boat of fixed speed crosses the river heading at all times towards its destination which is directly across the river from its starting point. The boat's path is animated.

I presume an experienced boat captain could constantly vary his heading so as to cross in a minimum time.

Can a function for this minimum crossing time heading be found and the worksheet altered to show the minimum time path?

  Rivercrossing.mw

Please can someone help with maple comand to obtain Jacobian elliptic functions particularly in code editing region?

Is there a way to specify different colors for different output variables? For example, if x,y, and z appear in the entire document as variables, I want x to be red, y to be blue, and z to be green whenever an output is displayed.

Thanks

will give me

which is indeed a solution of the PDE1

will give me

which is not a solution of the PDE2

However, both differential equations are equal, only the arguments are swapped around. Am I doing something wrong, or is this a bug?

Thanks

I'm trying project a plane onto a surface. Is there a direct command to do this?. There is a command to project a surface onto a plane but i need the oposite. Thanks!

I would like to publish a technical paper about a renewable energy with you. I use Maple 2016. What i need?. Thanks!

plot3d of procedure Sievert correctly displays the constant curvature Sievert surface, but the procedure uses the deprecated command evalm.

What Maple 2016 statement(s) would create the same value of X in Sievert?

Sievert := proc (B)

local a, b, denom, m, X;

a := sinh(B)*u; b := cosh(B)*v;

denom := sinh(B)*((cosh(2*a)-cos(2*b))*cosh(2*B)+2+cosh(2*a)+cos(2*b));

m := cosh(B)*[sinh(a), sin(b)*cos(v), sin(b)*sin(v)]+[0, -cos(b)*sin(v), cos(b)*cos(v)];

X := evalm([u, 0, 0]-8*cosh(B)*cosh(a)*m/denom);

end proc:

plot3d(Sievert(.75), u = -2.5 .. 2.5, v = -10.5 .. 10.5, scaling = constrained, grid = [30, 100], style = patch, shading = xy, lightmodel = light3, orientation = [-3, 140], title = "Sievert's surface", titlefont = [Courier, bold, 14]);

How can I ask Maple to plot intersection of two implicitplot3d? It is explained how to draw the union in the Maple help by simply entering a list to combine plots, but I didn't see anything about intersection.

Maple 2016 worked fine on July 27.

On July 28 Microsoft insisted on applying a patch to Windows 10 (they called it a "significant upgrade"). After that, Maple 2016 no longer works - it loads, presents the default worksheet, allows you to load a previous worksheet, but as soon as you go to do anything, it quits.

Any suggestions, other than downgrading to the previous version of Windows 10, which I have already done, (and turned off MS windows update services)?