I worked on a document about 2 hours ago. And now when I try to open it, it is empty. I saved it in MapleCloud, and I have had it saved before. So today I opnened the saved file from MapleCloud, but now it is gone. How can I get it back!!? It happend to two of my most important files..

PDE := diff(u(x, y), x, x)+diff(u(x, y), y, y)-6*x*y*(1-y)-2*x^3 = 0; BCsx := u(xL, y) = 0, u(xU, y) = y*(1-y); BCsy := u(x, yL) = 0, u(x, yU) = 0; solPDE := pdsolve({BCsx, BCsy, PDE}, u(x, y)); exactSol := unapply(rhs(%), x, y)

how i can write these boundary conditions for dsolve?

(diff(u(r), r))^(n-1)*(diff(r*(diff(u(r), r)), r))/r    be [finite] at r =0

and  u(0) = finite?

Thanks..

Hello!

I can't seem to figure out how to use the Physics package within a procedure. In particular, I can't get tensors to be recognized within the body of the proc.

As an example, here's a short program that works correctly when not in a procedure:

with(Physics):
Coordinates(X,quiet):
d_[mu](X[~mu]);
# Returns 4; Correct

However, placing this code inside a proc causes the tensor X to not be recognized as a tensor:

Test := proc()
  uses Physics:

  Coordinates(X,quiet):
  d_[mu](X[~mu]);
end proc:
Test();
# Returns 0; Wrong

Apparently, Physics:-Coordinates still defines the tensor X (as can be checked by calling Physics:-Define()). However, the derivative d_[mu] (X[~mu]) seems to be treating X as a standard symbol. Any idea how I would go about correcting this?

Thanks!

I am sure that this is a common enough problem. I want to show what commands I'm using to make an output in a maple worksheet in a latex document that i can include in a report.

So far I've got the export feature to work:

(here is an example mapleworksheet, texfile and a corresponding LatexProducedPDF),

but i can't see how to get it to include the commands that create the output.

Hello!

I want to use abstract linear operators between Lie algebras. I have the problem shown in the following short code:

with(LinearAlgebra): with(DifferentialGeometry): with(LieAlgebras):
LAr:=LieAlgebraData([ [e1,e2]=e3],[e1,e2,e3],LA);
DGsetup(LAr);
define(lin,linear);
lin(-e3);
lin(-LieBracket(e1,e2));
lin(LieBracket(e2,e1));

As you see, the minus "-" does not come out of the argument of lin() in the last line. What is going wrong?

Thanks!

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

Later on, I realized that the linear operator has nothing to do with the issue. The problem lies in the fact that the output of "LieBracket(e2,e1)" is "_DG([["vector", LA, []], [[[3], -1]]])" , where the latter "-1" refers to the coeffiecient. For some reason, this coefficient is not handled in the way I would expect. For example, the following two lines:

LieBracket(e2,e1)+LieBracket(e1,e2);
_DG([["vector", LA, []], [[[3], 1]]])+_DG([["vector", LA, []], [[[3], -1]]]);

give both as an output "e3+-e3" instead of "0", while both the lines

LieBracket(e2,e1) + LieBracket(e2,e1);
_DG([["vector", LA, []], [[[3], -1]]])+_DG([["vector", LA, []], [[[3], -1]]]);

give the output "2-e3" (which I interpret as "2(-e3)" ).

I don't understand what I am doing wrong.

I have PDE i trying to solve the equation using series.

pdsolve(diff(u(x, y), x, x)+diff(u(x, y), y, y) = Pi, series, order = 2);

Give me: "Error, (in DifferentialAlgebra:-RosenfeldGroebner) unexpected occurrence of the non-rational constants {Pi} in the given input" ?

pdsolve(diff(u(x, y), x, x)+diff(u(x, y), y, y) =gamma, series, order = 2);#gamma = 0.5772156649,Gives ERROR ?

If I  change instead of Pi is e or exp(1) works fine.

pdsolve(diff(u(x, y), x, x)+diff(u(x, y), y, y) = exp(1), series, order = 2);#OK.

It's a bug, design or  something else ?

How can one calculate isogeny of elliptic curves over finite fields in maple ?

I have a multiple integration. I know my integrals exist. When I write procedure for Rimannian sum, Maple gives correct answers for every choice of parameters of my integral. But when I ask Maple to compute it with int(...,numeric) sometimes it shows a correct answer and sometimes it shows a wrong answer. I'm curios to know what is going wrong in Maple, is there any command to see the details and steps of the computation to see where Maple is going wrong? I also increased the number of digits after decimal from 10 to 12 and 14. But Maple just repeats the wrong answers with just two or four digits. So the problem is not related to the approximation arising from number of decimals.

I was calculating the total derivative of a function but maple does not respond to the commands like alias,diff,totaldiff etc.

please see the attached pdf.multiplier.pdfmultiplier.pdf

fsolve does not any answer!!!!

please help me.

fsolve.mw

Dear users!

Hope everyone should be fine here. I need the following simiplification. I did it step by step is there and maple command to do this.

I am waiting your positive answer.

(diff(theta(eta), eta, eta))*(Rd*T[infinity]^3*(`θw`-1)^3*theta(eta)^3+3*Rd*T[infinity]^3*(`θw`-1)^2*theta(eta)^2+(3*(Rd*T[infinity]^3+(1/3)*epsilon*k[nf]))*(`θw`-1)*theta(eta)+Rd*T[infinity]^3+k[nf]) = (-3*Rd*T[infinity]^3*(`θw`-1)^3*theta(eta)^2-6*Rd*T[infinity]^3*(`θw`-1)^2*theta(eta)+(-3*Rd*T[infinity]^3-epsilon*k[nf])*(`θw`-1))*(diff(theta(eta), eta))^2+(-(rho*c[p])[nf]*nu[f]*f(eta)-(rho*c[p])[nf]*nu[f]*g(eta))*(diff(theta(eta), eta))+a*nu[f]*mu[nf]*(diff(f(eta), eta))^2/((-`θw`+1)*T[infinity])-2*a*nu[f]*mu[nf]*(diff(g(eta), eta))*(diff(f(eta), eta))/((`θw`-1)*T[infinity])+a*nu[f]*mu[nf]*(diff(g(eta), eta))^2/((-`θw`+1)*T[infinity])

(diff(theta(eta), eta, eta))*Rd*T[infinity]^3*(theta(eta)*`θw`-theta(eta)+1)^3+(diff(theta(eta), eta, eta))*k[nf]*(epsilon*theta(eta)*`θw`-epsilon*theta(eta)+1)+3*Rd*T[infinity]^3*(`θw`-1)*(theta(eta)*`θw`-theta(eta)+1)^2*(diff(theta(eta), eta))^2+epsilon*k[nf]*(`θw`-1)*(diff(theta(eta), eta))^2

diff((theta(eta)*`θw`-theta(eta)+1)^3*(diff(theta(eta), eta))*Rd*T[infinity]^3, eta)+diff((epsilon*theta(eta)*`θw`-epsilon*theta(eta)+1)*(diff(theta(eta), eta))*k[nf], eta);

when I  have transformed symbol expression  from matlab 2017b to  maple 2018 , maple took a mistake that  "maple kernel connection not available", What  is the  reason？Can anyone help me？Thank you！

fcns:=[u(x,y,t),v(x,y,t),h(x,y,t),c(x,y,t)]:

gr:=0.5:pr:=0.71:sc:=0.7:m:=1.0:k:=0.3:
  fcns:=[u(x,y,t),v(x,y,t),h(x,y,t),c(x,y,t)]:
  IC := [u(x,y,0)=0,v(x,y,0)=0,h(x,y,0)=0,c(x,y,0)=0]:
  BC:=[u(0,y,t)=0,h(0,y,t)=0,c(0,y,t)=0,u(x,0,t)=1,v(x,0,t)=0,h(x,0,t)=1,c(x,0,t)=1,u(x,10,t)=0,h(x,10,t)=0,c(x,10,t)=0];
  eq1:={diff(u(x,y,t),t)+u(x,y,t)*diff(u(x,y,t),x)+v(x,y,t)*diff(u(x,y,t),y)=diff(u(x,y,t),y$2)+gr*h(x,y,t)+gr*c(x,y,t)-m*u(x,y,t)
,diff(h(x,y,t),t)+u(x,y,t)*diff(h(x,y,t),x)+v(x,y,t)*diff(h(x,y,t),y)=1/pr*diff(h(x,y,t),y$2),diff(c(x,y,t),t)+u(x,y,t)*diff(c(x,y,t),x)+v(x,y,t)*diff(c(x,y,t),y)=1/sc*diff(h(x,y,t),y$2)-k*c(x,y,t)}:
  pds:= pdsolve(eq1,IC,BC,fcns,numeric):
  pds:= pdsolve(eq1,IC,BC,fcns,numeric,spacestep = 1/100):

for the above problem i made this code.