I would like to display an expression that is a matrix, the dot operator, and another matrix. That is, I want to display a multiplication of matrices, without the multiplication being evaluated.

Something like

<1,2;3,4> '.' <6,7,8,9>

Is this possible?

Here is some context around why I want to do this. Perhaps the main reason I use Maple is for the symbolic math capabilities using 2d math input. I want to create worksheets that look like what I would write on paper. 

For example, let's say I have a matrix that is defined by <I, F;0,0>, where each of elements is actually another matrix. I want to multiply this matrix by its transpose, which would be something like <I, 0^T; F^T, 0^T>.

I would like to display <I, 0^T; F^T, 0^T> .  <I, F;0,0>.

Hello guys
I created a document recently and, the next day, when I tried to open it, I received the following message:

        Recover corrupted file and save as

Does anyone know how to recover a corrupted file?
Regards,
Oliveira

Dear all

I would like to expand x^m using JacobiP  ( jacobi polynomials), with the two parameter alpha  and alpha +2, I have a result in my book using alpha and alpha+1 but i would like to get a similar result using alpha and alpha+2 

Inverse_formula_jacobi_polynomials.mw

Thank you 

I have a system of ODE's which are solved numerically (with rkf45) to get function values over time. And i have datapoints for these functions, and would like to compare and calculate the error/deviation between model and data. I can't find a command / mechanism that does this.

Is it possible?

I know maple help has exercies where you can learn from. I was, however, wondering if there is a standard place where people upload their specialized worksheets and maple documents they have used for research once they make it public.

Suppose I have a excel file with say 20 columns of data with equal number of rows of data. All numeric data

How to read each column data to a seperate variable

Or 

The entire data into a matrix 

The graph we draw in the graph theory package appear to be vectorial. So the export pdf is also clear. 

with(GraphTheory):
DrawGraph(PathGraph(2), stylesheet=[vertexborder=false,
vertexpadding=5,edgecolor = blue,vertexcolor=black,edgethickness=2],size=[250,250])

draw1.pdf

We know that DrawGraph only offers straight forms for drawn edges.  Sometimes we need to draw graphs with curves.  But when I try to use maple, I find that the vertices (by pointplot) are blurred after zooming in (or even without zooming out).

with(plottools):    
with(plots):
Bezier:=proc(x0,y0,x1,y1,x2,y2,x3,y3)
local f,g,c,l1,l2,l3,p0,p1,p2,p3;
f:=t->x0*(1-t)^3+3*x1*t*(1-t)^2+3*x2*t^2*(1-t)+x3*t^3:
g:=t->y0*(1-t)^3+3*y1*t*(1-t)^2+3*y2*t^2*(1-t)+y3*t^3:
c:=plot([f(t),g(t),t=0..1],thickness=2,scaling=constrained, color=blue,axes=none):
p0:=pointplot([x0,y0],symbol= solidcircle,symbolsize = 50,color=black):
p1:=pointplot([x3,y3],symbol= solidcircle,symbolsize = 50,color=black):
display(c,p0,p1,size=[300,300]);
end:

x0:=0:   y0:=0:
x1:=-0.2:  y1:=0.2:
x2:=0.5:  y2:=0.2:
x3:=0.3:  y3:=0:
p:=Bezier(x0,y0,x1,y1,x2,y2,x3,y3)

 draw2.pdf 

How to make these vertices vectorially drawn (like DrawGraph)？

If I have a set S:= [a,b,c],

I want the loop to give me: [[a,b,c],[a+b,c],[a+c,b],[a,b+c],[a+b+c]]

Consider the following matrix

Q := <cos(t), sin(t)>; sin(t), -cos(t)>

If I multiply the first column by the second column (at first glance this would see to be a 2x1 column multiplied by a 2x1 column, which isn't possible), I still get a result. 

(Q[1 .. 2, 1]) . (Q[1 .. 2, 2])

Now this isn't really that big a deal. Apparently, something like Q[1 .. 2, 1] is actually a Vector, so we're actually computing the dot product between two vectors. However, the result is the following

What is the bar over the variable t?

Hello

I wonder if there is a way to parallelize the function listed below.   It deals with a set of sets (dynamical systems).  As far as I can see the problem is with subs and simplify.  In some cases a division by zero shows up (the reason I added try..catch and had to use for). 

The procedure should remove the systems with imaginary coefficients and return the valid indices.  

Many thanks

Ed

Obs.:  The number of dynamical systems can easily be greater than 10,000.  Any speed improvement is welcome.

Example of one such a dynamical system is

[(-x*rho*xi[6]*(beta - 1)*sqrt(((rho + beta - 1)*sigma - beta + 1)^2*xi[8]^2/(beta - 1)^2) - xi[8]*(-2*y*sigma*xi[7]*xi[6]^2*(beta - 1)^2 + (sigma*rho + (sigma + 1)*(beta - 1))*x*rho*xi[6] + 2*sigma*z*rho^2*xi[8]))/(2*xi[6]*xi[8]*rho*(beta - 1)), (-(beta - 1)*(-y*sigma*xi[7]*xi[6]^2*(beta - 1)^2 + rho^2*(sigma*z*xi[8] + x^2))*xi[6]*sqrt(((rho + beta - 1)*sigma - beta + 1)^2*xi[8]^2/(beta - 1)^2) - (2*sigma*(beta - 1)^2*(y*xi[7]*(rho + beta - 1)*sigma/2 + x^2*rho + y*(beta - 1)*xi[7]/2)*xi[6]^3 + 2*x*z*rho*sigma*xi[8]*(beta - 1)^2*xi[6]^2 + (-z*xi[8]*(rho + beta - 1)*sigma^2 + ((2*beta^2*z - 3*beta*z + z)*xi[8] + x^2*rho - (beta - 1)*(-2*beta*y*xi[7] + x^2))*sigma + x^2*(beta - 1))*rho^2*xi[6] + 2*x*z*rho^3*sigma*xi[8])*xi[8])/(2*xi[8]*sigma*(beta - 1)*(rho^2 + (beta - 1)^2*xi[6]^2)*xi[6]*xi[7]), (-(-x*sigma*(beta - 1)^2*xi[6]^3 + (beta - 1)^2*(sigma*y*xi[7] + x^2)*xi[6]^2 - rho^2*sigma*x*xi[6] - sigma*z*rho^2*xi[8])*(beta - 1)*rho*sqrt(((rho + beta - 1)*sigma - beta + 1)^2*xi[8]^2/(beta - 1)^2) + xi[8]*(-2*y*sigma^2*xi[7]*(beta - 1)^4*xi[6]^4 + 2*(rho*(rho + beta - 1)*sigma/2 + (beta - 1)*((-beta + 1/2)*rho + y*(beta - 1)*xi[7]))*sigma*(beta - 1)^2*x*xi[6]^3 + (beta - 1)^2*(((-y*xi[7] + 2*z*xi[8])*rho + y*(beta - 1)*xi[7])*sigma^2 + (x^2*rho + (beta - 1)*(-2*beta*y*xi[7] - 2*beta*z*xi[8] + x^2 + y*xi[7]))*sigma - x^2*(beta - 1))*rho*xi[6]^2 + 2*(rho*(rho + beta - 1)*sigma/2 + (beta - 1)*((-beta + 1/2)*rho + y*(beta - 1)*xi[7]))*sigma*x*rho^2*xi[6] + xi[8]*sigma*z*((rho - beta + 1)*sigma - beta + 1)*rho^3))/(2*xi[8]^2*sigma*(beta - 1)*rho*(rho^2 + (beta - 1)^2*xi[6]^2))]

coefmodel

{beta = 8/3, rho = 28, sigma = 10}

and phi and coe equal to 

[[], [], []]

cleanSystems := proc(sys::list,phi::list,coe::list,coefmodel::{list,set})
description "This function applies coefficient values to a system and remove it if the coef is somehow imaginary":
local i,aaa:=table(),bbb:=table(),ccc:=table(),ind:=table():
for i from 1 to nops(sys) do
  try
   aaa[i]:=simplify(subs(coefmodel,sys[i])):
   if has(aaa[i],I) then
      aaa[i]:=NULL:
      bbb[i]:=NULL:
      ccc[i]:=NULL:
      ind[i]:=NULL:
   else
      bbb[i]:=simplify(subs(coefmodel,phi[i])):
      ccc[i]:=simplify(subs(coefmodel,coe[i])):
      ind[i]:=i:
   end if:
  catch:
   aaa[i]:=NULL:
   bbb[i]:=NULL:
   ccc[i]:=NULL:
   ind[i]:=NULL:
  end try:
end do:
aaa:=convert(aaa,list):print(nops(aaa)):
bbb:=convert(bbb,list):print(nops(bbb)):
ccc:=convert(ccc,list):print(nops(ccc)):
ind:=convert(ind,list):print(nops(ind)):
return(aaa,bbb,ccc,ind):
end proc:

How to plot Nabla Discrete Mittag - Leffler Function in Maple?

For the attached worksheet "insert contents" worked two month ago. My computer settings have not changed since.

The same happens with an empty worksheet (document mode) created with 2022.2

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/Unit_of_t.mw .

Download Unit_of_t.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/empty.mw .

Download empty.mw

How can we unveil all the possible transformations that reduce the number of independent variables of a given pde? I tried it by using "InvarientSolutions" which gives eight possible transformations. But under those transformations, I got only two different odes. Is there any other method/command from which we can get other possible odes of a given pde?

pde_ode.mw

The transformed boundary conditions are

Please and please, I have been having this challenge for some time now and I would be so so happy if I can get a solution to my challenge. I have been worried on:

how do I use these definitions (Volterra Integral Equation and Caputo definition) to solve

Helper, please. You can use any definition you are familiar with also. Only I need a fractional definition.

Thanks