Good day.

Reading the documentation on Physics package in Maple, I did not find information about how Maple handle dummy indices of tensorial expressions. For example, suppose I have the following tensorial expression in Maple: 

    A[mu] * B[~mu] 

with dummy index mu. Then I want to apply the following simple substitution rule:

    A[alpha] = C[alpha]*C[mu]*C[~mu]  

Here, free index alpha should be...

I would like to plot the following expression that I call W

>W:=tau*exp(C4)/C1-exp(C4)*(exp(C3-C3*eta)/C3^2-exp(C3)/C3^2+tau/C1+eta/C3)+exp(C4-C3*eta/2)*Sum(16*beta[m]*sin(beta[m]*eta/2)*exp(-(beta[m]*beta[m]+C3^2)*tau/(4*C1))/((beta[m]*beta[m]+C3^2)*( beta[m]*beta[m]-C3^2)^2),m=1..n)

Where C1, C3, C4 are constant, and  beta[m]satisfies the relationship  

C3*sin (beta/2) =beta*cos (beta/2)

I want to plot the W-eta curve and W-tau curve (eta at [0, 1...

Dear sir i  want the contour values  automatically display on the contour.

Hear is the code and sample contour plot. 

contourplot(x^5-y^3,x=-5..5,y=-4..3,axes=boxed,contours=10);

Hi all,

What else could I try if I encounter this error?

Warning:  Incomplete separation.

--------------------------------

 

I read the pdsolve help page, where it says I should have a solution with this warning, but I got nothing but the error.

 

Dear Maple users

I am working on a problem, which basicly is dealing with putting n identical marbles in k different boxes. I need to run through all possible combinations and do something with it. The latter is unimportant. Mathematics say there are binomial(n+k-1,k-1) different combinations. I have already produced a recursive procedure to solve the problem and it is displayed below. I have placed a counter in the procedure to control if the procedures get through...

Hello,

I would like to assign a value I got from using the command 'Maximize'. What I gained as an answer is of the following form:
test:=[1234124, [t=124124124]] 

Now my point is to assign both these values to variables, which I can do for the first like:
first:= test[1];

But I just can't find out how to assign the second value.
I was trying it out by using the command 'rhs' but that doesn't work (although, not for me).

Probably a silly question, but yeah..thanks for a reply.

Frank 

Dear all,

I'm trying to substitute a combination of variables in an equation that is partly covered in a summation.

For example consider the equation with two variables A and B, and two function W(t) and q(z):

now I want to do the substitution:

ptr_mplprims.mwHello,I am trying solve  a travelling force problem with pdsolve, but I cannot obtain the second derivative of the solution. I obtained the first derivative, with help from another post (http://www.mapleprimes.com/questions/80997-Derivative-From-Numeric-PDE-Soln#comment81512). When I tried doing the same thing for the second derivative it didn't work. Any sugestions would be helpful. Thank you!!!

Hello all, 

I have the system which consists of three linear first-order differential equations (see below). First, I solved this system numerically backward in time by implying the final condition for the variables at time t=T (i.e, x(T=4)=10 and so on) and depicted the graph. Then, from the obtained solution I found the values of the variables at time t=0 and solve once again the system of ODE's but forward in time with...

Say I have the equation:

f:=x^5+a*x^4+b*x^3+c*x^2+d*x+e

and I want to introduce an identity namely

x^3:=1

Since

subs(x^3=1,f)

or

eval(f,x^3=1)

doesnt work I wonder what is the most elegant way to implement this?

Hello,I just can't find out whether it's possible to plot the x-axis 'below' the graph? Normally speaking the x-axis is plotted at y=0, but I want my x-axis to be plotted for example at y=-5 or y=-10. Can that be done?Greetings,Frank

Why does maple not simplify this expression any further:

-4*cos((1/5)*Pi)*m^3-4*cos((1/5)*Pi)*n^3-4*cos((1/5)*Pi)*p^3-4*cos((1/5)*Pi)*q^3+4*cos((2/5)*Pi)*m^3+4*cos((2/5)*Pi)*n^3+4*cos((2/5)*Pi)*p^3+4*cos((2/5)*Pi)*q^3-10*cos((1/5)*Pi)*p*q^2+10*cos((2/5)*Pi)*m^2*n+12*cos((2/5)*Pi)*m^2*p+12*cos((2/5)*Pi)*m^2*q+12*cos((2/5)*Pi)*m*n^2+10*cos((2/5)*Pi)*m*p^2+12*cos((2/5)*Pi)*m*q^2+12*cos((2/5)*Pi)*n^2*p+10*cos((2/5)*Pi)*n^2*q+12*cos((2/5)*Pi)*n*p^2+12*cos((2/5)*Pi)*n*q^2+12*cos((2/5...

with(PIR):
RPP:='PIR/homalg';

'homalg/default':=RPP;

Error, illegal use of an object as a name

var:=[I];PIR['Pvar'](var);

test1 := (3*f-f^2)*(Diff(g, x))+(-f+3*f^2-2)*(Diff(g, y))+(2-f^2)*(Diff(g, z));

test1r := solve(test1=0,f);

 

how to solve this in terms of Diff(g,x), Diff(g,y) etc.

after solve, it is like a bug, because result is Diff(1,x) etc where is g?

 

Hi,

Say for a 126 by 18 symbolic matrix, substituting numerical values into the matrix DD1 takes about 10 seconds (using time() );

for a 62 by 16 matrix, take just about 1/5 second.

By when the matrix is about 254 by 20, it take much longer! More than a minute!

I never actually waited how long, but I am wondering if there is something wrong? Am I using the right command?

Say the matrix is DD1 with numpar:=[x=0.3,y=0.2,z=0.98,....]