## Inversion of high dimension matrices...

Hi
How we can obtain inversion of the high-dimensional matrix (for example 600*600) in maple?
(A fast-time command)
thanks

## initial vaule problem...

i want someone hlep me in this worksheet the diff eq of complex i want to sovle it with any numeric method

 >
 >
 >
 >
 (1)

 >
 (2)
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 >
 (3)
 >
 >
 >
 >
 >
 >
 >
 >
 >
 (4)
 >
 (5)
 >
 (6)
 >
 >

## Evaluate and print values...

how to evaulate the value of R(z) for different values of z=0 to 1 with an interval of 0.1 and print ten values  in one column

R(z):= 1-cos^2*(Pi*z);

## Fractional-order expansion of a function ...

Hi
I am trying to expand a function f(t) in terms of fractional power series:
for example please see attached file tree.mw

 >
 >
 >
 >
 >

thanks

## PDE_and_BC_during_2018_err...

Hello, to all,
On my computer I have installed Windows 7 Professional, Maple 2018.2.1 and
Physics:-Version()[2];
2019, January 5, 13:32 hours, version in the MapleCloud: 276,

version installed in this computer: 276
When I try to compute some examples from your poste "PDE_and_BC_during_2018.mw", I get an error in Example 8:
Example 8: This problem represents the temperature distribution in a thin circular plate whose lateral surfaces are insulated (Articolo example 6.9.2):
pde__8 := diff(u(r, theta, t), t) = (diff(u(r, theta, t), r)+r*(diff(u(r, theta, t), r, r))+(diff(u(r, theta, t), theta, theta))/r)/(25*r);
/
|
|
|
d                    1   |/ d                \
pde__8 := --- u(r, theta, t) = ---- ||--- u(r, theta, t)|
dt                  25 r |\ dr               /
\

2                  \
d                   |
-------- u(r, theta, t)|
/  2                \          2               |
| d                 |    dtheta                |
+ r |---- u(r, theta, t)| + -----------------------|
|   2               |              r           |
\ dr                /                          /
iv__8 := D[1]*u(1, theta, t) = 0, u(r, 0, t) = 0, u(r, Pi, t) = 0, u(r, theta, 0) = (r-(1/3)*r^3)*sin(theta);
iv__8 := D[1] u(1, theta, t) = 0, u(r, 0, t) = 0,

/    1  3\
u(r, Pi, t) = 0, u(r, theta, 0) = |r - - r | sin(theta)
\    3   /
pdsolve([pde__8, iv__8], u(r, theta, t), HINT = boundedseries(r = [0]));
Error, (in dsolve) cannot determine if this expression is true or false: not 0 <= -Pi

or I get no answer as in Example 10:
Example 10: A Laplace PDE with one homogeneous and three non-homogeneous conditions:
pde__10 := diff(u(x, y), x, x)+diff(u(x, y), y, y) = 0;
/  2         \   /  2         \
| d          |   | d          |
pde__10 := |---- u(x, y)| + |---- u(x, y)| = 0
|   2        |   |   2        |
\ dx         /   \ dy         /
iv__10 := u(0, y) = 0, u(Pi, y) = sinh(Pi)*cos(y), u(x, 0) = sin(x), u(x, Pi) = -sinh(x);
iv__10 := u(0, y) = 0, u(Pi, y) = sinh(Pi) cos(y),

u(x, 0) = sin(x), u(x, Pi) = -sinh(x)
pdsolve([pde__10, iv__10]);

There are also no answer as in Examle 10 in the Examples 15, 18, 19
Can you give me a hint,  what could be wrong?
With kind regards
Wolfgang Gellien

## DifferentialGeometry x Physics...

Hello everyone!

I am trying to calculate the Killing vectors for the metric below. For such, I used the packages DifferentialGeometry and Physics. However, I found different results these packages. Could someone explain why?

killing_test1.mw

killing_test2.mw

## Maintain Sequence Iterator In Same Line...

So I was trying to create a shorthand for creating a plot of multiple arrows, with the arrow colour dependent on the magnitude of the vector.
I currently have a set of vectors, v, I want to display, and v[4] is the largest.

I know this could be done by creating an arrow plot for each vector seperately and then by combining them using display:
arrow1 := arrow( v[1], width=0.15,length=20,color=ColorTools:-Color( (norm(v[1])/norm(v[4]))*[0,0,1] ) );
arrow2 := arrow( v[2], width=0.15,length=20,color=ColorTools:-Color( (norm(v[2])/norm(v[4]))*[0,0,1] ) );
...
print(plots:-display([arrow1, arrow2, ...]));

But I was wondering if it could be done in a fashion similar to this:
arrows := arrow([seq(v[i], i=1..4)],width=0.15,length=20,color=ColorTools:-Color((norm(v[i])/norm(v[4]))*[0,0,1]));
print(arrows);

(btw: it works fine replacing the last i with 1, which draws all arrows nearly black, or with 4, which as you guessed, draws all arrows blue...)

Help appreciated!

## Open source Maple install for ubuntu 18.04...

Look I have actually purchased the software 3 time in total throughout my life, but i have no money at this point but i have a Linux OS now and i am enjoying learning how to use that, so i was wondering if there is a standard old verson that is open source and availble for a Linux install

## How do I plot a Fourier series for each values of ...

Sum of -(2*((-1)^n-1))*sin(n*Pi*x)*exp(-Pi^2*n^2*t)/(Pi*n) from n=20??? Thank you very much

## How to create Action in Maplet with 'for - do' com...

I try to use command "for a in 1,2 do Tangent(f, x = a) end do" in my Maplet but it does not work.

Here it is:

[Button("Tangent line", Action( Evaluate(for a in 'solve(diff(func, x) = slp, x)' do 'MMLV1'='MathML[Export]('y'=Tangent(func,x=a))' end do)))],

And here is all code for my Maplet

> restart:with(Maplets[Elements]):with(Student[Calculus1]):  TL2:=Maplet([ ["Input function  f(x)=", TextField['func'](20)],[Button("Display function",Action(Evaluate('MMLV'='MathML[Export](func)')))],MathMLViewer['MMLV'](), ["Input slope", TextField['slp'](10)],  [Button("Tangent line", Action( Evaluate(for a in 'solve(diff(func, x) = slp, x)' do 'MMLV1'='MathML[Export]('y'=Tangent(func,x=a))' end do)))],   MathMLViewer['MMLV1']()   ]):  Maplets[Display](TL2):
print(`output redirected...`); # input placeholder

## Error in creating array using loop...

I am trying to create an array whose elements are from another matrix. Suppose I have a matrix of n cross m dimension my array will have a dimension of 1 cross n*m. When I create  array I am getting error. The array contains only last element of matrix. The expected answer is given in attachment.

sigma.mw

## GraphTheory: True/false-statement comparing list o...

Suppose there is a list with edges (L1): [{3,5},{4,3},{4,6},{3,2},{2,6}] and a list with vertices (L2): [1,5,4].

I would like to get a true-statement when a number of L2 appears in one of the edges of L1.

I tried the following:

for i in L1 do

ME:=member(i,L2):
print(ME):

od:

This only gives false-statements. Could anyone help me?

## pdetest fails when called after another pdetest...

I found a case where pdetest fails when called after another call to pdetest. I am using Physics version 272 from the clould. Using Maple 2018.2.1 on windows 10

restart;
u:='u';x:='x';t:='t';
pde := diff(u(x, t), t) + diff(u(x, t),x) =0;
sol:=pdsolve(pde,u(x,t));
pdetest(sol,pde);
#0  OK

#restart;
u:='u';x:='x';t:='t';
pde:=diff(u(x,t),t)+diff(u(x,t),x)=0;
bc:=u(0,t)=0;
ic:=u(x,0)=sin(x);
sol:=pdsolve([pde,ic,bc],u(x,t)) assuming x>0;
pdetest(sol,pde);

#sol := u(x, t) = -sin(-x+t)*Heaviside(-t+x)   #OK

#-Dirac(-t+x)*sin(x)*cos(t)+Dirac(-t+x)*cos(x)*sin(t)+
Dirac(-x+t)*sin(x)*cos(t)-Dirac(-x+t)*cos(x)*sin(t)   #WRONG should be 0

If I run the above again, but with restart call in between active, so that all is cleared, then pdetest gives 0 as expected on the second pde, with the same solution

restart;
u:='u';x:='x';t:='t';
pde := diff(u(x, t), t) + diff(u(x, t),x) =0;
sol:=pdsolve(pde,u(x,t));
pdetest(sol,pde);
#0   #OK

restart;
u:='u';x:='x';t:='t';
pde:=diff(u(x,t),t)+diff(u(x,t),x)=0;
bc:=u(0,t)=0;
ic:=u(x,0)=sin(x);
sol:=pdsolve([pde,ic,bc],u(x,t)) assuming x>0;
pdetest(sol,pde);

#0   #OK !!

can any one explain why this happens?  Is this a bug? It seems like pdetest caching problem. it remembers something from the last call and this affects the result it gives for the next call.

any work around?

## What ius wrong here?...

Another GCD attempt. Why is there a parse problem? Thanks

 >
 >
 >
 >
 >

## Why is procedure unterminated?...

I do know that Maple has a gcd command but I am just experimenting

 >
 >
 >
 >
 >