Good afternoon sir.

I request your kind suggestion to the above cited query.

With thanks & Regards

M.Anand

Assistant Professor in Mathematics

SR International Institute of Technology,

Hyderabad, Andhra Pradesh, INDIA.

Hi,

1-Triying to plot a function divided by its maximum value,sometimes it works with some parameters that means, the max.value of the plot is 1.

But when i change the data the max. value in the plot in graeter than 1 which is wrong!! should be 1.

dont know why??

2- Changing different data in the parameters, the programme takes long long time then i stop it?

please help me with these two problems.

restart:
>
------------------------- Defining the nature of the variables used ----------------------
assume(T,real):Digits:=25:n:=1:tau:=Pi:
theta:=0:phi:=0:
lambda:=n;Omega:=1:Gamma:=0.01:
--------------------- Input---------------------------------
1

J1

term1:=(exp((Gamma+I*d)*tau)-1)/(2*(Gamma+I*d)):
Ak1:=d->(exp((Gamma+I*(d+0.5*Omega-2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d+0.5*Omega-2*lambda*k/Gamma))+(exp((Gamma+I*(d-0.5*Omega+2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d-0.5*Omega+2*lambda*k/Gamma)):
Ak2:=d->(exp((Gamma+I*(d-0.5*Omega-2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d-0.5*Omega-2*lambda*k/Gamma))+(exp((Gamma+I*(d+0.5*Omega+2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d+0.5*Omega+2*lambda*k/Gamma)):
term2:=(evalf(-0.25*sum(BesselJ(k,Omega*Gamma/(4*n))*Ak1(d)+BesselJ(k,-(Omega*Gamma)/(4*n))*Ak2(d),k=0..50))):
J1:=(term1+term2):
J1mod:=(Re(J1))^2+(Im(J1))^2:
###### J2#########################
Ak1:=d->(exp((Gamma+I*(d+0.5*Omega-2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d+0.5*Omega-2*lambda*k/Gamma))-(exp((Gamma+I*(d-0.5*Omega+2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d-0.5*Omega+2*lambda*k/Gamma)):
Ak2:=d->(exp((Gamma+I*(d-0.5*Omega-2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d-0.5*Omega-2*lambda*k/Gamma))-(exp((Gamma+I*(d+0.5*Omega+2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d+0.5*Omega+2*lambda*k/Gamma)):

J2:=(evalf(-0.25*sum(BesselJ(k,Omega*Gamma/(4*n))*Ak1(d)+BesselJ(k,-Omega*Gamma/(4*n))*Ak2(d),k=0..100))):
######################

J2mod:=(Re(J2))^2+(Im(J2))^2:
J3 same as J1differ in sign
term1:=(exp((Gamma+I*d)*tau)-1)/(2*(Gamma+I*d)):
Ak1:=d->(exp((Gamma+I*(d+0.5*Omega-2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d+0.5*Omega-2*lambda*k/Gamma))+(exp((Gamma+I*(d-0.5*Omega+2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d-0.5*Omega+2*lambda*k/Gamma)):
Ak2:=d->(exp((Gamma+I*(d-0.5*Omega-2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d-0.5*Omega-2*lambda*k/Gamma))+(exp((Gamma+I*(d+0.5*Omega+2*lambda*k/Gamma))*tau)-1)/(Gamma+I*(d+0.5*Omega+2*lambda*k/Gamma)):
term2:=(evalf(0.25*sum(BesselJ(k,Omega*Gamma/(4*n))*Ak1(d)+BesselJ(k,-Omega*Gamma/(4*n))*Ak2(d),k=0..100))):
J3:=term1+term2:
J3mod:=(Re(J3))^2+(Im(J3))^2:
J4 same as J2 but -0.25-->2

J4:=-2*J2:
######################

J4mod:=(Re(J4))^2+(Im(J4))^2:

calculate the spectrum

Spec:=d->(exp(-2*Gamma*tau)*(J1mod*cos(theta/2)^2+J2mod+J3mod*sin(theta/2)^2-0.5*Re(J3*J4*sin(theta)*exp(I*phi))+0.5*Re(J1*J4*sin(theta)*exp(-I*phi)))):

with(plots):

tit:=sprintf("l=%g,W=%g,G=%g",lambda,Omega,Gamma):
Smax1:=max(seq(evalf(Spec(d)),d=-100..100)):
plot(evalf(Spec(d)/Smax1),d=-15..15,axes=boxed,title=tit,color=black,font=[2,3,18],thickness=2,tickmarks=[3,3],titlefont=[SYMBOL,14],font=[1,1,18],linestyle=1);

I have a multivariate polynomial P (written with the order "tdeg")in the (x_i)_i ; the coefficients are functions of the (a_i)_i. I'd want the set of the monomials that appear in the development of P. For instance P=a_1xy^2z^3+a_2x^4yz^2+a_3 is associated to {xy^2z^3,x^4yz^2,1}. Does there exist a command to do that ?

In a second time, I'd want the coefficients of {xy^2z^3,x^4yz^2,1} in the same order. Does there exist a command to do that ?

Thanks in advance.

HI,

Here is my question,

I want to plot dependent variable or say function f(x) on x-axis and independent variable x on x-axis. But dont know how to do it. Please help me for this.

Regards

Sunit

Hello,

I look for solving a DAE system i obtain after having determined the equations of a mechanical system with kinematic closed loops.

For that, thanks to the partitioning method, i could transform my DAE in ODE system.

But now, i don't manage to solve my ODE system.

The first issue was the calculation of big matrix with trigonometric functions. With your help in the post "Resolution of a big product of matrix with trigonometric function" (http://www.mapleprimes.com/questions/200012-Rsolution-Of-A-Big-Product-Of-Matrix) , i could calculate the different matrix involved are calculated.

Now, the resolution with my differential system is very long and never finished.

@Carl Love 3670 gives me good advices. He asked me to try to avoid symbolic calculations of the matrix.

Do not use the output option for dsolve.

Then the following procedure evaluates the Matrix AA:

AA:= proc(S,t)
local Cu_inv:= eval(Cu, S(t))^(-1), tCu_inv:= eval(tCu, S(t))^(1);
     eval(Avv - Avu.Cu_inv.Cv + tCv.tCu_inv.Auu.Cu_inv.Cv - tCv.tCu_inv.Auv, S(t))
end proc:

           To use it, invoke AA(Sol, t) where t is an actual numeric value.

Unfortunately, i don't see how i can use this method for the moment? But, i think that there is a step i don't understand. For me, i have to make the calculation of the big matrix AA and QQ before solving my differentiel system because my differentiel system is composed with AA and QQ.

Here you can find the system i try to solve.

and here you can find the maple file without the steps leading to the setting of the equations

calcul_des_matrices_.mw

Find a loop do define these matrices, even for large values of n. Record the Matrix Mn 

all i,j=1,2,13,..,n for example 

N := `<|>`(`<,>`(1, 2), `<,>`(2, 2))

P := `<|>`(`<,>`(1, 2, 3), `<,>`(2, 2, 3), `<,>`(3, 3, 3))

Q := `<|>`(`<,>`(1, 2, 3, 4), `<,>`(2, 2, 3, 4), `<,>`(3, 3, 3, 4), `<,>`(4, 4, 4, 4))

Please help!!!

Hello,

       I have a huge sparse matrix (1.5e6 x 1.5e6) of both symbolic or non-symbolic form. When I export matrix using ExportMatrix command, it is not writing the matrix in order of rows and columns. To further explain the problem,

          Let A be that huge sparse matrix. I am using

                    ExportMatrix("matrix.mtx",A,format=MatrixMarket)

We expect the output to be,

 1 1 0.1

 1 10 0.65

.

.

.

But it is writing the output as

 

100 1 0.25

100 25 0.65

Hence it is not writing in order. What is the way we can force it to write in order? I do understand using for loop will consume more time.

I have two equations:

and I need to extract the coefficients of x0 and xp0 (to build a matrix; but that is not the issue). So I use coeffs:

coeffs(op(2,X),x0);

coeffs(op(2,XP),x0);

xp0

While I can live with the first result (for X) (not that I like it), the fact that the 2nd one (for XP) has a completely different structure prevents any kind of algorithmic extraction of the coefficients (and the second one of course is 0) for further use. I tried the form of coeffs with a third argument (a name which gets the result assigned) but the same result. This example is a real case, obviously a trivial one and others will be much more involved so I really would like this to work. And yes, I did "collect" before using coeffs (not that it was needed here).

Any ideas out there?

Mac Dude.

I am trying to plot a function f(x).  Within the definition of f(x) I have some parameters, e.g., a, b, c tha have been defined.  Then these three parameter define a new parameter R.

The function is f(x)=R x.

a := 1;              Define a
1

b := 2;              Define b
2

c := 3;               Define c
3

R = a+2*b+3*c; Define R from a, b, c

R = 10 + 2 b~ (it should had given me 14)

F(x):=R*x;  Define the function
x -> R x

plot(R*x, x = -5 .. 5);   RECEIVE ERROR
Warning, expecting only range variable x in expression R*x to be plotted but found name R

I also tried to define R as R(a,b,c) and then F as F(R,x)...

but still it doesnot work.

Can anyone direct me to the right solution?

Thanks in advance.

NM

Hello All,

I have had a few questions that have come up while working on a Maple Assignment for my Calculus III class. I was wondering if anybody could help me with these questions, as well as show me how to enter them in Maple. Here are the questions I have been struggling with.

1. In the xy-plane, graph the ellipse ((x-4)^2)/(4))+(y-4)^2=1 and two level curves of F(x,y)=x^3+y^3-3xy that just touch the ellipse.

                  a. What do we know about the gradients of F and the ellipse at those points?

                  b. Use your graph to approximate the minimum and maximum values of F subject to the constraint ((x-4)^2)/(4))+  (y-4)^2=1.

      2. A company manufactures a product using inputs x,y,z according to the production function Q(x,y,z)=20x^(1/2)y^(1/4)z^(2/5). The prices per unit are $7 for x, $12 for y, and $18 for z.

                 a. Create the cost function

                 b. The company wants to produce 2500 products. Estimate the minimum cost by using the graph of the level surfaces of the cost function (from part a) together with the production constraint.

Any help you could give me would be much appreciated. Thanks!!

In some tutorials for certain "Maple-words" a name "command" is used, while others use "function".

What is the difference between "function" and "command" in Maple?

I have list for a:=[11110, 10101,100,10101], but, this list i want assume that all number is base 2..
so, how i want to convert to base 10?

Is it possible to use Unicode characters in  textplot  command? In the application that I'm developing, the signs of the chess pieces should be used.

I am trying to figure out how to enter tensors using the new Physics package in 17.02. For my first, presumably simple example, I am trying to reproduce the Lorentz transformation in Special Relativity:

X^μ' = Λ_ν^μ X^ν

where

Λ_ν^μ = [{γ, -γβ, 0, 0}, {-γβ, γ, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}]

X^ν = [x0, x1, x2, x3]^T

My Λ tensor Defines just fine; I do

(which, upon <Enter> is labeled (1)), and then

Define((1))

and this suceeds. However, when I do the X vector:

which is labeled (2), then the Define((2)) function returns the following error:

Error, (in Physics:-Define) expected right-hand-side of tensor definition as an algebraic tensorial expression, or a Matrix or an Array, representing the evaluation rule for the tensor X[`~nu`]; received: Vector(4, {(1) = x0, (2) = x1, (3) = x2, (4) = x3})

So my question is, what is the correct syntax for Defining or declaring a vector to be a tensor?

(Also, incidentally, why is the covariant (superscript) index ~nu being displayed as a subscript when Maple echoes my entry?)

Thank you,

Kevin

So, newb question here. I've done my best to debug this line of code, but to no avail. For some reason this function is NOT getting solved correcting for the zeros:

cos(L*x) - x*sin(L*x)

This is not an extremely complex equation either, so I'm at a loss for why my while loop continues to sit there forever. I've got it set to find N number of zeros, but it'll just keep going forever never finding any zeros. I've tried mixing up the start point, and even changed the range which it's searching for them, but nothing seems to get me any closer. Please help!

> restart; with(plots);
> a := 0; b := 1/2; N := 5; w := 1; L := b-a;

Eigenvalue equation
> w := cos(L*x)-sin(L*x)*x;
> plot(w, x = 0 .. 50);

> lam := array(0 .. N+1);

> nn := 0; kk := 5; while nn < N do zz := fsolve(w(x) = 0, x = kk .. kk+1); if type(zz, float) then printf("lam(%d)=%f\n", nn, zz); lam[nn] := zz; nn := nn+1 end if; kk := kk+1 end do