MaplePrimes Questions

restart;
with(DEtools);
assume(r::real, a::real, b::real, upsilon::real, sigma::real, x::real, y::real, t > 0);
assume(sigma > 0); assume(-b^2-r+2 > 0);
V := -2*exp(I*(sqrt(-b^2-r+2)*x+b*y+r*t))*sqrt(1/sigma)*sech(-t*(-2*sqrt(-b^2-r+2)-2*b)-x-y):
pde[1] := I*(diff(V, t))+diff(V, x, x)+diff(V, y, y)+sigma*abs(V^2)*V = 0: evalc(pde[1]);

 

solution.mw

Dear All

I seldom need support, Maple/MapleSim usually runs OK, but here I'm stuck with MapleSim 2017 I'm modelling some thermal fluid properties and each time I make a sub-system I get two errors:

1) the entries (and exit variables) "rho, Cp, Cv, lambda, and nu" of my models are set to default "1" instead of my expected value the names of my fluid-parameter items. I must rename them by hand to be able to solve my model, why not a link to the fluid parameter node ?

2) I get a pressure p (or is it a "rho"?) issue: "Cannot resolve `Main.Block1.p`; there is no `p` in variable `Main.Block1`" when I create a sub-system I call here Block1 and my model does not solve if I make any "sub-systems", and I cannot find out what to do, is this an initial value issue ? the error message could be more helpful ;)

Any clues how to get around this ?

Thnaks in avance

Sincerely

Ivar

I do not know what I am doing wrong. I am trying to plot each of the solutions to an ODE. One of the solutions Maple gives is  LegendreQ((1/2)*sqrt(5)-1/2, x) and the other is LegendreP((1/2)*sqrt(5)-1/2, x)

Maple can plot the  LegendreP, but gives an error plotting LegendreQ((1/2)*sqrt(5)-1/2, x)

ode:=(1-x^2)*diff(y(x),x$2)-2*x*diff(y(x),x)+y(x)=0:
sol:=dsolve(ode,y(x));

sol := y(x) = _C1*LegendreP((1/2)*sqrt(5)-1/2, x)+_C2*LegendreQ((1/2)*sqrt(5)-1/2, x)

Now when I do 

plot(LegendreQ((1/2)*sqrt(5)-1/2, x),x=-1..1);

Maple says

Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct
 

Why is that? I tried x=-0.5..1 and x=0.5..1 and keep getting same error message. It works ok for 

plot(LegendreP((1/2)*sqrt(5)-1/2, x),x=-1..1);

Mathematica can plot both with no problem.

Dear all

Represent

x+(( y^(2+x) )-4)/3

as a binary tree and rewrite this expression in postfix notation

Can this quesiton be solved using maple

Many thanks

 

the graph of tan (x) and the graph of the tangent line ( at pi/4). the graph of arctan x, and the graph of the tangent line of arctan x at x=1.

4 graphs (on the same set of axis)

BVP := [4*(diff(u(x, t), t))-9*(diff(u(x, t), x, x))-5*u(x, t) = 0, u(0, t) = 0, u(6, t) = 0, u(x, 0) = sin((1/6)*Pi*x)^2];
pdsolve(BVP);
        
U := unapply(rhs(sol), [x, t]);
  
plot3d(eval(U(x, t), infinity = 20), x = 0 .. 6, t = 0 .. 4);
Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct

 

 

Hi Users!

Hope everyone in fine and enjoying good health. I am facing problem to differential the following expression with respect to first variable (mentioned as red). Please help me to fix this query

f(z*sqrt(a/nu[f]), U*t/(2*x))

Thanks in advance

create the sequence of exp (((aπ) / b)) for a varying from 1 to 15 and b varying from 1 to 10.

Hey.
I have been trying to convert my maple .mw file to a PDF under 'Print...' but it does not work. The problem is when I click on the "Save as PDF" and I name my pdf and click on 'Save' it does not save my file anywhere. It simply will not save it. 
Does somebody know why it will not save as a PDF? It saves all other files properly (also converts word files to PDF fine). 

 

Can I somehow define a function based on a result from a PolynomialFit.
It doesn't seem to read it as a function the way I try to define it now (see attached maple file).

I could copy the result into a function, but then I lose some information since the values are approximated.

Define.mw

dS[c] := Gamma*(P*In[a]+R[a]+S[a])-rho*S[c]-S[c]*beta[h]*In[v]/(S[c]+In[c]+R[c]+S[a]+In[a]+R[a]+In[m])-mu[h]*S[c]; dIn[c] := S[c]*beta[h]*In[v]/(S[c]+In[c]+R[c]+S[a]+In[a]+R[a]+In[m])-rho*In[c]-gamma*In[c]-mu[h]*In[c]; dR[c] := gamma*In[c]-rho*R[c]-R[c]*mu[h]; dS[a] := rho*S[c]-S[a]*beta[h]*In[v]/(S[c]+In[c]+R[c]+S[a]+In[a]+R[a]+In[m])-mu[h]*S[a]; dIn[a] := rho*In[c]+S[a]*beta[h]*In[v]/(S[c]+In[c]+R[c]+S[a]+In[a]+R[a]+In[m])-gamma*In[a]-mu[h]*In[a]; dR[a] := gamma*In[a]+rho*R[c]-R[a]*mu[h]; dIn[m] := Gamma*In[a]*(1-P)-mu[m]*In[m]; dS[v] := Gamma[v]-S[v]*beta[v]*(In[c]+In[a]+In[m])/(S[c]+In[c]+R[c]+S[a]+In[a]+R[a]+In[m])-mu[v]*S[v]; dIn[v] := S[v]*beta[v]*(In[c]+In[a]+In[m])/(S[c]+In[c]+R[c]+S[a]+In[a]+R[a]+In[m])-mu[v]*In[v]; solve({dIn[a]=0, dIn[c]=0, dIn[m]=0, dIn[v]=0, dR[a]=0, dR[c]=0, dS[a]=0, dS[c]=0, dS[v]=0}, {In[a], In[c], In[m], In[v], R[a], R[c], S[a], S[c], S[v]}); Warning, solutions may have been lost

Display integers between -10 and 20. Put integers between -10 and 20 in a list.

Display the odd integers between 115 and 231, then put them in a list

Construct a procedure that takes as argument a sorted list, an element n and returns the place of n if it belongs to the list, the sequence NULL otherwise.

Hi, I am trying to run the following command in a Maple worksheet

P:= 1979 #(this is the1000-th prime);
S:=5000; k:=5:
a:=[0$i=1..k];
f:=[0$i=1..k];
a[1]:=S;
f:=x->a[1];
with(RandomTools):
for i from 2 to k do
a[i]:=Generate(integer(range=1..P-1));
f:=x->f(x)+a[i]*x^(k-1);
print(f(x));
od;

(This is a beginning step to create the Shamir's secret sharing).
However, I get the following output (with explanations)

                              5000          (This is correct. the value a[1])
x -> a[1]                                   (This should be the initial function f = 5000)
                              7005          (This is correct, the value a[2])
x -> f(x) + a[i] x^(k-1)               (one of the main problems, see below)

The main problems are in the last output above:
1. The f(x) is not as it should be: f(x) = a[1] = 5000;
2. The index i isn't changed when it should be i = 2;
3.  An error message: too many levels of recursion  

The output (I expect) should be: 5000 + 7005x, ...., etc.

Thanks in advanced for any help.

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