Maple 18 Questions and Posts

These are Posts and Questions associated with the product, Maple 18

How to clear this error and frame the series

FWF.mw

Hi every one

I need a command or simple procedure to convert an ODE into a linear polynomial.

For example, let us consider the ode in the attached file. I want to return the poly in this file. draft1.mw

Could you please help me?

How to find the series.I'm getting this error.Please help to solve this.

AF.mw

How to plot this equation

 y(x):=

where,

A := Matrix([[1, -1, 1, -1], [1, 1, -1, -1], [-1, 1, 1, -1], [1, 1, 1, 1]]);
B := Matrix([[1], [0], [1], [0]])

i want to find fitted parameter value for G1,G2,G3,tau1,tau2,tau3 and plot stress-strain curve that fit to true_stress_strain curve(experimental data)
and i tried many times and still get error..can anyone please help me.here is my maple file...
 prony.mw 

Could you please help me to solve this error.

my code is here.

CR-C.mw

Please Help.

I have solve this problem in Runge-Kutta Method but i'm getting error.Can you solve this in RK Method or How to give a code for Shooting Method.

Here is my code.

 HNF1.mw

X is a real random matrix of dimension n; its entries are i.i.d. variables.

They follow the standard normal law N(0,1).

I want to write a big sample. For that, I use the following two lines:

roll := RandomVariable(Normal(0, 1))

X := Matrix(n, proc (i, j) options operator, arrow; (Sample(roll))(1)[1] end proc)

Is there a method that does the calculations faster ??

Thanks in advance.

eq1 := diff(f(x), x, x, x)+(1/2)*x*cos(alpha)*(diff(f(x), x, x))+(1/2)*sin(alpha)*f(x)*(diff(f(x), x, x))+G[r]*theta(x)+G[m]*phi(x) = 0;

eq2 := diff(theta(x), x, x)+(1/2)*Pr*cos(alpha)*x*(diff(theta(x), x))+sin(alpha)*f(x)*(diff(theta(x), x))+N[b]*(diff(theta(x), x))*(diff(phi(x), x))+N[t]*(diff(theta(x), x))^2 = 0;

eq3 := diff(phi(x), x, x)+(1/2)*Le*cos(alpha)*x*(diff(phi(x), x))+sin(alpha)*f(x)*(diff(phi(x), x))+N[t]*(diff(theta(x), x, x))/N[b] = 0;

ics := f(0) = 0, (D(f))(0) = gamma*((D@@2)(f))(0), theta(0) = 1+tau*(D(theta))(0), phi(0) = 1;

bcs := (D(f))(infty) = 0, theta(infty) = 0, phi(infty) = 0;

Parameters := G[r] = 5, G[m] = 3, Pr = 7, N[b] = .1, N[t] = .1, Le = 1, gamma = .2, tau = .1, alpha = 30*degree;

I have a equation

((D@@2)(theta))(eta) = -(1/2)*(D(theta))(eta)*(-2*(D(phi))(eta)*beta*epsilon*lambda*D[B]+2*(D(phi))(eta)*beta*epsilon*mu*D[B]+f(eta)*sin(alpha)*beta*nu+2*(D(theta))(eta)*gamma*epsilon*D[t]-2*(D(theta))(eta)*beta*epsilon*D[t]+cos(alpha)*beta*eta*nu)/(beta*sigma)

and a parameters expression

Pr:=nu/sigma; N[b] := epsilon*D[B](mu-lambda)/sigma; N[t] := epsilon*D[t](gamma-beta)/(gamma*sigma); Le := nu/D[B]

How can I seperate common terms and substitute this parameters and got this following expression

((D@@2)(theta))(eta) = -(1/2)*Pr*(D(theta))(eta)*eta*cos(alpha)-(1/2)*Pr*(D(theta))(eta)*sin(alpha)*f(eta)-N[b]*(D(theta))(eta)*(D(phi))(eta)-N[t]*(D(theta))(eta)

How to conver a patial differetial equation to ordinary differential equation with or without dchange?
 

restart

declare(u(x, y, t), v(x, y, t), T(x, y, t), C(x, y, t), eta(x, y, t), psi(x, y, t), f(eta), theta(eta), phi(eta));

declare(u(x, y, t), v(x, y, t), T(x, y, t), C(x, y, t), eta(x, y, t), psi(x, y, t), f(eta), theta(eta), phi(eta))

(1)

eta := proc (x, y, t) options operator, arrow; y/(nu*t+nu*x/U[w])^(1/2) end proc:

eq1 := diff(T(x, y, t), t)+u*(diff(T(x, y, t), x))+v*(diff(T(x, y, t), y))-sigma*(diff(T(x, y, t), y, y))-epsilon*D[B]*(diff(T(x, y, t), y))*(diff(C(x, y, t), y)) = 0

diff(T(x, y, t), t)+U[w]*(D(f))(y/(nu*t+nu*x/U[w])^(1/2))*(diff(T(x, y, t), x))+(-(1/2)*f(y/(nu*t+nu*x/U[w])^(1/2))*nu/(nu*t+nu*x/U[w])^(1/2)+(1/2)*(D(f))(y/(nu*t+nu*x/U[w])^(1/2))*y*nu/(nu*t+nu*x/U[w]))*(diff(T(x, y, t), y))-sigma*(diff(diff(T(x, y, t), y), y))-epsilon*D[B]*(diff(T(x, y, t), y))*(diff(C(x, y, t), y)) = 0

(2)

``


 

Download pde_to_ode.mw

i want to plot this equations for P and t for  t= 0 t0 600 seconds..can u provide me how?

time-dependent_aerodynamic_pressure.mw

restart

k := 0.1e-1;

0.1e-1

 

5

(1)

`P₀₀` := 100;

100

(2)

V := 25;

25

(3)

rho := 1;

1

 

.5

(4)

eq := diff(P(t), t) = -k*P(t)+rho*Cp*(int(V*sin(alpha), t));

diff(P(t), t) = -0.1e-1*P(t)+12.5*sin(5)*t

(5)

solution := dsolve({eq, P(0) = `P₀₀`}, P(t));

P(t) = 1250*sin(5)*t-125000*sin(5)+exp(-(1/100)*t)*(100+125000*sin(5))

(6)

``

Download time-dependent_aerodynamic_pressure.mw

restart;

eq32r:=diff(B(r),`$`(r,3))+diff(B(r),r);

diff(diff(diff(B(r), r), r), r)+diff(B(r), r)

(1)

with(PDEtools, casesplit, declare); with(DEtools, gensys):declare(b(r), prime = r);

[casesplit, declare]

 

b(r)*`will now be displayed as`*b

 

`derivatives with respect to`*r*`of functions of one variable will now be displayed with '`

(2)

eq32r;

diff(diff(diff(B(r), r), r), r)+diff(B(r), r)

(3)

latex(eq32r);

{\frac {{\rm d}^{3}}{{\rm d}{r}^{3}}}B \left( r \right) +{\frac

{\rm d}{{\rm d}r}}B \left( r \right)

 

#instead of {\frac {{\rm d}^{3}}{{\rm d}{r}^{3}}}B I want to have B''' in my latex file.

``

``

Download convert-latex.mw

Hi everybody

I have a differential equation where derivatives (for example d/dr) have been displayed by prime notation.

I want to convert this equation latex format by keeping the prime notation not d/dr.

I would appreciate it if anyone could help me.

I have attached a sample code.

Thank you

Hadi

Hello everyone! I have found this document from Maple 18 (2014) that will be very usefull for my school work, but when i copy it into Maple 2022 i get the error message, "action, does not evaluate to a module" Is there any way for me to fix this? What i have been able to read is that i have to go in and update the code, but i have absolute no idea on how to do it? 

Kind Regards Samuel 

Regressionmodeller._Skal_laves_til_maple_22_og_23.mw

could any one help  to plot this.

Here is my code.

PWS.mw

I need to make the graph i have attached match the image below.

Is there any wrong with unknown parameter i found?How to solve this.Please Help.

1 2 3 4 5 6 7 Last Page 3 of 87