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Change index in SUM...

Yesterday at 9:20 AM sarra 100

Hi,

I have

Let

A:= sum(a[n]*phi(n)+b[n+1]*phi(n+2),n=0..N);

Please, I need to write this sum, using only phi(n), how can I use maple to get the solution.

Thank you very much for any idea.

 

 

 

 

 

 

 

I’m trying to figure out how to find a basis for a subspace, V, of Rdefined by V = {(x, y, z)l(2x-3y+6z=0)}

 

I’m using the student linear algebra module for maple 17

 

I’ve tried defining the subspace and asking for the basis of V but I always get an error code.

 

I’ve tried consulting the maple website and looking through their help menu, but can’t find anything that answers how to find a basis... At least a basis from the subspace defined in my problem.

I know how to find a basis for the subspace by hand but not with maple.

Any help will be greatly appreciated. 

How can I solve x^2 on -Pi..Pi and to evaluate this at x= Pi to prove that Sum(1/n^2, n= 1..infinity) = Pi^2/6.

 

Dear All, I need your help to plot the numerical solution. many thanks.

The variable t in [0,T], x in [0,1], b in [0,2].

Difference finie for waves equation is :

pde:=diff(u(x, y,t), t$2) = c^2*(diff(u(x, y,t),x$2)+diff(u(x,y,t),y$2));

i: according to x, j according to y, and k according to t.

u[i,j,k+1]=2*u[i,j,k]-u[i,j,k-1]+(c*dt/dx)^2*(u[i-1,j,k]-2*u[i,j,k]+u[i+1,j,k])+ (c*dt/dy)^2*(u[i,j-1,k]-2*u[i,j,k]+u[i,j+1,k])

 

Boundary condition: u(t=0)=1, diff(u(x,y,t),t=0)=0, and the normal derivative on the boundary of Omega =0.

How can solve this problem and plot the numerical solution.

 

 

 

Hi

I need a temperature distribution inside a barrier during a heating process.
I will be appreciated for any help.

 

wz

How to animete BC using varying temperature in time?  How to obtain animated solution?

restart

Diffusivity coefficent...

a := 0.1e-5:

Thickness of barrier...

L := .2:

Heating curve:
Time in heating curve (in hours form exmaple)...

Time := seq(i, i = 1 .. 10):

Varying temperature in time [K]....

Temp_in_Time := [433.15, 568.15, 703.15, 838.15, 973.15, 1108.15, 1243.15, 1378.15, 1513.15, 1616.15]:

Initial temperature [K]

Tot := 298:

PDE := diff(T(x, t), t) = a*(diff(T(x, t), x, x)):

--->>>

BC1 := {T(0, t) = Temp_in_Time[2], T(L, t) = Temp_in_Time[2], T(x, 0) = Tot}:

sol := pdsolve(PDE, BC1, numeric, timestep = 50):

sol:-plot(t = 3*3600, thickness = 3, colour = red);

 

``



Download heating.mw

 

Hi. Thanks to help me in ths question.

 

t:=[1,2,3];

f(t[1])=[3,4];  f(t[2])=[11,12];   f(t[3])=[41,1]; 

How can plot  f  versus t

 

 

 

 

Hi.

Please help to use dsolve.

Suppose I have a Matrix A of size two. Y=[u,v].

Y'(t)=A*y(t).

How can use dsolve this problem.

Thanks

 

 

 

 

Hi

 

I have some data:

Matrix(10, 2, {(1, 1) = 0, (1, 2) = 0, (2, 1) = .5, (2, 2) = 3.25, (3, 1) = 1.0, (3, 2) = 5.82, (4, 1) = 1.5, (4, 2) = 7.50, (5, 1) = 2.0, (5, 2) = 8.79, (6, 1) = 2.5, (6, 2) = 9.83, (7, 1) = 3.0, (7, 2) = 10.66, (8, 1) = 3.5, (8, 2) = 11.35, (9, 1) = 4.0, (9, 2) = 11.94, (10, 1) = 4.5, (10, 2) = 12.46})

 

I want Maple to make a trendline fitting a Logarithmic function. I can make it output some function with this:

LeastSquares(`<,>`(.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5), `<,>`(3.25, 5.82, 7.50, 8.79, 9.83, 10.66, 11.35, 11.94, 12.46), x, curve = a+b*ln(x))

It outputs:

5.96497783539274+4.25309474196387*ln(x)

 

But please notice, the dataset in the function does not have the first 0 and 0. If i do that:

LeastSquares(`<,>`(0, .5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5), `<,>`(0, 3.25, 5.82, 7.50, 8.79, 9.83, 10.66, 11.35, 11.94, 12.46), x, curve = a+b*ln(x))

It outputs: 

Error, (in Matrix) numeric exception: division by zero

 

Besides that, i need the R-squard value for determinating how well it fits.

 

If i do the same thing i Excel the data set will give a formular: 5.5464ln(x)-0.2175 with a R-sward value of 0.9985.

 

How can i do this i maple?

 

Thanks in Advance!

 

----

Emil Kristensen

Thank you for your help with this question. I found what I was looking for. 

Dear All,

I have a simple question, Thanks of your remarks

I would like to find the slope of a line:

 

I Want to find the slope of this line. How????

In ode solve command i generated a large array data. The output shows a large order matrix of this form

 

[110001x6 Matrix

Datatype:Anything

Storage:rectangular

order:Fortran_order].

 

I want to export this matrix into a notepad. Which can then be used for plotting in TecPlot. 

 

Looking for good response

 

 

Hi,
i am trying to built a maplet which can encode and decode.  for example i have Ceasar encryption codes and i want to built a maplet that can do it. 

you can see below one of my try: encode is working but decode didnt work :/ what should i do?

restart:
with(Maplets[Elements]):
with(StringTools):

alphabet := convert([97, 98, 99, 231, 100, 101, 102, 103, 240, 104, 253, 105, 106, 107, 108, 109, 110, 111, 246, 112, 114, 115, 254, 116, 117, 252, 118, 121, 122],bytes): 

code:= letter -> SearchText(letter,alphabet)-1:
char := i -> alphabet[i+1]:
modulus := Length(alphabet): 
shift := proc(key);
i -> (i+key) mod modulus;
end:

CaesarEnc :=()-> Action(Evaluate('cpmessage'= 'Implode(map(char,map(shift('ky'),map(code,Explode('text')))))')):

CaesarDec := () -> Action(Evaluate('cpmessage' = 'CaesarEnc(-'ky','text')')):

Caesar := Maplet(Window('title'= "Caesar Encoding And Decoding", BoxLayout['BL1']( BoxColumn('halign'=left,
BoxRow(Label['l1']("Write message: ",'width'=100,'halign'=left), TextBox['text']('background'=white,'foreground'= brown,'height'=6,'editable'=true,'width'=50)),BoxRow(Label['l2']("Key: ",'width'=100,'halign'=left), TextBox['ky']('background'=white,'foreground'= black,'height'=3,'editable'=true,'width'=50)),Button("Encode",'onclick'=CaesarEnc()), Button("Decode",'onclick'=CaesarDec()),BoxRow(Label['l3']("Text: ",'width'=100,'halign'=left), TextBox['cpmessage']("",'background'=white,'foreground'= blue,'height'=6,'editable'=false,'width'=50) ))))):
Maplets[Display](Caesar);

i need to do it for my thesis. waiting for your answers, thank you :)

Dear people being here,

I have a question.

When I wrote as

aa:=(delta[1]*n[1])/(n[f1]*delta[1]);

maple returned as 

aa := n[1]/n[f1]

How can I have maple express the original one, aa:=(delta[1]*n[1])/(n[f1]*delta[1]), not what returned to me?

I hope you will answer to my question.

And, thanks in advance.

 

taro

I am to program a computation on maple.
But I get the message :

Error, unable to match delimiters

followed by the full sequence of command.

 

How can I do to fix this problem?

Can someone explain to me, if you can, how the Euler angles on the plot interface work?

 

It looks like Phi is the rotation around z, Theta is the rotation around x, and Psi is around y. I'm trying to use matrices to compute the vector that is pointing towards your face as you're looking at the plot with the given Euler angles.


X := Matrix(3, 3, {(1, 1) = 1, (1, 2) = 0, (1, 3) = 0, (2, 1) = 0, (2, 2) = cos(phi), (2, 3) = sin(phi), (3, 1) = 0, (3, 2) = -sin(phi), (3, 3) = cos(phi)});


Y := Matrix(3, 3, {(1, 1) = cos(theta), (1, 2) = 0, (1, 3) = sin(theta), (2, 1) = 0, (2, 2) = 1, (2, 3) = 0, (3, 1) = -sin(theta), (3, 2) = 0, (3, 3) = cos(theta)});


Z := Matrix(3, 3, {(1, 1) = cos(psi), (1, 2) = sin(psi), (1, 3) = 0, (2, 1) = -sin(psi), (2, 2) = cos(psi), (2, 3) = 0, (3, 1) = 0, (3, 2) = 0, (3, 3) = 1});

and computing X*Y*Z*e3

 

TIA!

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