## Error, unable to execute add...

How to clear this error and frame the series

FWF.mw

## How can convert an ODE to a linear polynomial?...

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

AF.mw

## How to plot a equation with matrix?...

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]])

## plaease help this least square or curve fitting pr...

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

my code is here.

CR-C.mw

## How to solve this?...

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.

## Sample of random matrix. Normal law....

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 ??

## How do I solve boundaty value problem with derivat...

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;

## How to simplify and substitute parameters in expre...

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 Convert PDE to ODE?...

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

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 (2)
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## how to plot these equations ...

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

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 (1)
 >
 (2)
 >
 (3)
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 (4)
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 (5)
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 (6)
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## Converting to Latex ...

 > restart;
 > eq32r:=diff(B(r),\$(r,3))+diff(B(r),r);
 (1)
 > with(PDEtools, casesplit, declare); with(DEtools, gensys):declare(b(r), prime = r);
 (2)
 > eq32r;
 (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.
 >

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

## Updating a maple document code from 2014 to 2022 v...

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