I have a nonlinear partial diff eq which I am sure has been categorized.  How do I go about finding literature on the eq & the approach to solve it.  I have visited various websites that have catalogs of nonlinear partial diff eq's.  The problem is notation is so NONSTANDARD I have no IDEA what I am reading.  I have included a PDF eq_of_choice.pdf with my notation which I am familiar with. ...

Included below is vector partial diff eq I am working with.  To get rid of the time deriv's I took the LaPlace transform & the remaining spatial eq in the s-domain is listed.  To make matters simpler I set beta = 0 to get rid of the curl of the field.  What remains is essentially the Helmholtz eq.  To simplify further I just found the homogeneous soln for the x direction only.

As can be seen the eigenfunctions are exponentials with s beneath...

gam := 1.4;
p[L] := 1;
u[L] := 0;
rho[L] := 1;
p[R] := 1;
u[R] := 1;
rho[R] := 1;
p1 = 1/2*(p[L]+p[R]);
A[L] := 2/((gam+1)*rho[L]);
A[R] := 2/((gam+1)*rho[R]);
B[L] := (gam-1)*p[L]/(gam+1);
B[R] := (gam-1)*p[R]/(gam+1);
a[L] := (gam*p[L]/rho[L])^(1/2);
a[R] := (gam*p[R]/rho[R])^(1/2);
if p1 > p[L] then
     f[L] := (p1-p[L])*(A[L]/(p1+B[L]))^(1/2);
     df[L] := (A[L]/(p1+B[L...

Hello,

These days I thought a question:how to creat a variable delay?

As illustrated in Fig.1, if delay time T is constant, then the output is y(t)=u(t-T), so we can use a block named "Pade Delay" in maplesim to achieve our purpose.As shown in Fig.3.

If delay time is variable,namely,T(t), then the output is y(t...

Hi All,

I'm new here and to Maple and this is my first post.

How do I get maple to evalaute the following expression:

sum(exp(-1/2*(((psi-theta) + 2*pi*n) / (sigma))^2), n=1..infinity);

psi and theta are angles, sigma is a constant - basically psi, theta and sigma are numbers. In fact the summation is where n is a member of Z (set of integers) but I will be happy with a solution for n= 1..infinity.

when I eval an expression at one x value it works but why does eval fail to work when multiple values of x are passed on to eval as a list....

a:=x^2

eval(a,x=9) will result in 81.

But eval(a,x=[9,10]) does not produce   81,100 .

I was under the impression that multiple values of x can be passed on as a list. Please let me know where I am making mistake(s). Thanks in advance !!

I am thinking about using Maple for my math calculations and work. Is Maple going to be around and vibrant since its acquisition by a Japanese software group? Just wanted to make sure I am not investing time and resources in a technology that might be phased out. Thanks in advance!

I need help with unapply command in order to create functions out of solutions produced by the solve command. For example, I want to solve ax^2+bx+c=0 and create a function out of the first of the two results. Thanks in advance!!

How can I use the eval command to evaluate x^2 at  [5,7]. I know how to eval x^2 at just x=5 or just x=7 but I am not sure how to evaluate the entire list [5,7]. Thanks in advance !!

what is the purpose behind the command gc()  ? Thanks in advance !!

Some time after I start using Maple 13 I notice that the scroll bar on the right is choppy. I also notice similar issues when I plot a 2D graph with the plot and the scroll bar becoming choppy. Could this be a computer memory problem? I am using Maple 13 on Windows XP with 1.25GB RAM. Thanks in advance !!

Please help me with function mapping.

I want to map 1/x over the list [2,6,8]. 

Thanks in advance !!

Solving the system

 a1 := 2*x2-x3-x4-x5-x6-x7;
 a2 := -2*x1+2*x3-x4-x5-x6-x7;
 a3 := x1-2*x2+2*x4-x5-x6-x7;
 a4 := x1+x2-2*x3+2*x5-x6-x7;
 a5 := x1+x2+x3-2*x4+2*x6-x7;
 a6 := x1+x2+x3+x4-2*x5+2*x7;
 a7 := x1+x2+x3+x4+x5-2*x6; b := x1+x2+x3+x4+x5+x6+x7;
 solve({x1 >= 0, x2 >= 0, x3 >= 0, x4 >= 0, x5 >= 0, x6 >= 0, x7 >= 0,
 b = 1, a1 <= 0, a2 <= 0, a3 <= 0, a4 <= 0, a5 <= 0, a6 <= 0, a7 <= 0},...

Are there naming conventions or requirements for uploaded files?

I am used to using something like "name.rlm.xx.yy.Mvv.mw" with spaces as appropriate in the name. xx.yy is my version, because I save many versions as I go along. Mvv is the Maple version.

Are there some names that MaplePrimes will not handle correctly, aside from length?

Though I have been a casual Maple user since M12, I really don't know how to use it well, and am just learning it. I set myself a few tasks to help me discover its potential. I find that I learn better if I have some goal, even if it is just a sample goal.

In the accompanying file, I want to see how to use M14, and explore how to use Legendre polynomials.

Q: In (3.4), is there a cleaner way to declare the sequence?

Q: Am I using sequences correctly in this file?

I am trying to duplicate the material that is shown in the accompanying PDF file, where the plot actually comes from the calculations, much as I am trying to do with Maple 14.

Q: (3.9) gets the correct coefs, but not very pretty...is there a better way?

Q: I eventually stumbled upon (3.10), which looks correct, but when I dragged it to the plot and dropped it, I got only the first Legendre polynomial, not n of them. How do I get that?

Q: How do I show that I dropped L on the plot? The legend shows Curve 1 and 2.

Q: Is there a way to combine (3.8) and (3.9) into one stem, for example, by using array subscripts? I tried and failed.

Legendre_polynomial_.mw

Legendre_polynomial_.pdf