Auto paste last entry

So maple uses % as the last expression entry.  My suggestion is to use Crtl+Space on the % command to re-display the last expression.  Yes one could easily use the mouse to select the last entry then Crtl+c and Crtl+v. 

Or maybe the command Crtl+Shift+L to auto paste last entry. 

**edit** actually I would prefer the Crtl+Shift+L option to auto paste the last entry.

** Appears to be a suggestion I made earlier https://www.mapleprimes.com/questions/148867-Is-There-A-Way-To-Recallrepeat-Previous

Hello

I want to declare 'd' as a constant.

Please tell me how to declare 'd' as a constant.

intersection de deux droites l1 et l2 telles que l1 sous forme parametrique est [57/5 + 20*t, -21/5 - 40*t, 20*t] et de la meme façon

 l2 [249/100 - 120*t, 471/100 - 80*t, 200*t]. t est le parametre  . maple donne pour l'intersection de l1 et l2 le point P de coordonnes

 [249/100, 471/100, 0] que je ne trouve pas .expliquez moi ce resultat et merci beaucoup.

I have a big matrix which is computed in a worksheet, now I have to use this matrix in another worksheet. Could you recommend some ways of healthy transferring of quantities between worksheets?

with(plots);
with(LinearAlgebra);
A := Matrix([[2, 1, 0, 0, 3], [0, 2, 1, 0, 0], [0, 0, 2, 1, 0], [0, 0, 0, 2, 1], [0, 0, 0, 0, 2]]);
sparsematrixplot(A, matrixview, color = "Red", symbol = "cross");

How do I change the plot to show other symbols? Even though I write for example "cross" I still get the default box.

Also, is there a way in which I can let the color depend on the number in the matrix? Right now it just shows all non-zero entries.

restart:
digits := 20;
unprotect(D);
G := 0.04361098108*x^2 + 0.4810001561*x*y + 1.326278064*y^2 - 0.7320831383*x - 2.656083763*y + 1 = 0
f := (x, y) -> lhs(G);
coeffs(f(x, y));
A, B, C, D, E, F := coeffs(f(x, y));
A := coeff(f(x, y), x, 2);
B := coeff(coeff(f(x, y), x), y);
C := coeff(f(x, y), y, 2);
D := coeff(coeff(f(x, y), x, 1), y, 0);
E := coeff(coeff(f(x, y), y, 1), x, 0);
F := tcoeff(f(x, y));
expand(B^2 - ((4*A) . C));
                          digits := 20

   f := proc (x, y) options operator, arrow; lhs(G) end proc

  1, -0.7320831383, 1.326278064, 0.04361098108, 0.4810001561, 

    -2.656083763

A, B, C, D, E, F := 1, -0.7320831383, 1.326278064, 0.04361098108, 

  0.4810001561, -2.656083763

                       A := 0.04361098108

                       B := 0.4810001561

                        C := 1.326278064

                       D := -0.7320831383

                       E := -2.656083763

                             F := 1

                               0.

with(geometry):
_EnvHorizontalName := 'x': _EnvVerticalName := 'y':
conic(co,f(x,y),[x,y]):
detail(co);
                 /                            
   GeometryDetail\["name of the object", co], 
   ["form of the object", ellipse2d], 
   ["center", [1.212351672 ^(10, 10), -2.198412833 ^(10, 9)]], 
   ["foci", [[2.424703344 ^(10, 10), -4.396825668 ^(10, 9)], 
   [0.1787052775, 0.9855002601]]], 
   ["length of the major axis", 2.464245740 ^(10, 10)], 
   ["length of the minor axis", 66579.62094], 
   [                                               2
   ["equation of the ellipse", 1. + 0.04361098108 x 
                                      2                 
    + 0.4810001561 x y + 1.326278064 y  - 0.7320831383 x
                       ]\ 
    - 2.656083763 y = 0]/;
   "_noterminate";

G is a parabola with B^2-4*A*C=0 or an ellipse ? A =1 or F=1 ? Thank you for youy answer. 

I need the Infinitesimals(Lie group analysis) of the system of PDE. I have attached below the system of PDE in MAPLE given below.MAPLE_Help.mw

Thank you

I have code which in module which does this

           DEtools:-kovacicsols(ode,func)

Where ode is some ode and func is y(x).  When I step in the debugger, I get exception at this. It says

       DBG> DEtools:-kovacicsols(ode,func)
       Error, `DEtools` does not evaluate to a module

Same exact code works OK from worksheet as expected.   SO for some reason, inside this module it does not see DEtools and I have no idea why.

Then I tried with :-  before DEtools, but this did not help. it gives

DBG> :-DEtools:-kovacicsols(ode,func)
Error, `table([(dperiodic_sols)=proc () `DEtools/init`() <> 0; `ODEtools/intfactor`(_passed); end etc...
` does not evaluate to a module

In a worksheet, it all works OK

ode:=diff(diff(y(x),x),x) = (-3/16/x^2-2/9/(x-1)^2+3/16/x/(x-1))*y(x);
func:=y(x);
DEtools:-kovacicsols(ode,func)

Gives the solution with no error.

Any suggestion what could be the cause and what to try next? I never seen anything like this. I am running this code using 

interface(warnlevel=4);
kernelopts('assertlevel'=2):

I am able to make a MWE. It seems this always happens in the debugger.  But if  I let it run, it works somehow. Only when I try to step into it, it gives error. Here is MWE

interface(warnlevel=4);
kernelopts('assertlevel'=2):
foo:=proc(ode,func)
   local result;
    DEBUG();   
    result:=DEtools:-kovacicsols(ode,func);
    return result;
  end proc;

And now

ode:=diff(diff(y(x),x),x) = (-3/16/x^2-2/9/(x-1)^2+3/16/x/(x-1))*y(x);
func:=y(x);
foo(ode,y(x))

Now in the debugger if I do DEtools:-kovacicsols(ode,func) or if I stepin the call, I get the error. But I hit the continue botton, I do not get the error and it gives solution. 

Why this happens?

Maple 2021.2 on windows 10

@acer,
In the past, you had shown how to use take a given sparse A matrix and store the LU components and use the same factorization for multiple backsolves at https://www.mapleprimes.com/posts/41191-Solving-Sparse-Linear-Systems-In-Maple#comment200817

When PDEs are solved, we are calling the A matrix at every time step (with some discretizations in x) and the factorization is done and stored at every time step (this is time-consuming and memory-consuming). Is it possible to call UMFPACK using only the sparse storage and entries? The main routine seems to provide the option 

https://people.sc.fsu.edu/~jburkardt/f77_src/umfpack/umfpack.html

This would mean that the pattern is found only once for the Jacobian at t= 0, then only the non-zero sparse entries (vector/row, not a matrix) are updated at every time step.

To be clear, what I am asking for is create a random sparse matrix (say 4x4 or 10x10)
create a b Vector.

Solve AZ =b with method = SparseDirect. (This should internally create and store R, CC, X as at https://people.sc.fsu.edu/~jburkardt/f77_src/umfpack/umfpack.html)

Store R, CC, X and update only X for a different A matrix with the same sparsity pattern and solve for Z using stored (R, CC), and updated X.

j'ai deux spheres concentriques s1 et s2  de centre O(-1,-1,-1) de rayon respectivement 3 et 2. mais maple donne que FindAngle(s1,s2)=arcos(31/12). comment expliquez ceçi et merci beaucoup.

PDETWOSTEPVARIAMETHOD.mwPDETWOSTEPVARIAMETHOD.mw

Pls i need help to correct this iteration code, I wrote but is not given the correct answer. find attached the worksheet

Hi again everybody,
I hope this can help in some classrooms.

This procedure has some warnings.  Someone else can clean it up.
Also, the ithprime() command can make it a bit slicker.
I did work with prime constelations project, and you can see my web page at mattanderson.fun  .

Refference oeis.org/A40 .
Some prime constelations, and k-tuples, are not of 'general intrest' yet, so they are not in the OEIS encyclopedia YET!

But prime numbers are exciting.  I like doing calculations.

Hopefully someone in the next generation will take up an intrest and do what I did.

pairs_procedure.mw

pairs_procedure.pdf

I wish the best on all of you.

Regards,

Matt C. Anderson

which kind of input is DeepLearning:-Optimizer(GradientDescent()) suppose to take? Nummeric value or function?

Hi!

I am fairly new to maple and needing to use it for my project this year. I have been advised to use it to help solve the following integral:

int(2/(1-x^p)^(1/p), x=0..1)

It will give me the answer I am looking for, however I cannot get it to explain the steps to get the answer. I have tried Student Calculus1 and ShowSolution but neither of them seem to be working.

Any help would be really appreiacted!

Hello Sir
Hope you are fine. I am facing issues in integration evaluations. I have attched code and pic as well. Kindly guide me. I am waiting for your kind response.
Thanks

question.mw

Download question.mw