with(DifferentialGeometry):with(JetCalculus):
DGsetup([x],[u],E,5);
vars≔x,u,u[1],u[1,1],u[1,1,1];
PDEtools[declare](Q(vars));
TotalDiff(Q(vars),x);
TotalDiff(u[1,1],x);

Hi everyone,

Recently I came across the total differentiation command in the PDEtools. For its

documentation, I used the following link

http://www.maplesoft.com/support/help/Maple/view.aspx?path=DifferentialGeometry/JetCalculus/TotalDiff

Unfortunately, when I try to replicate this it did not work as expected. I am getting the total derivative of the expression to be zero. I do not understand where I am going wrong.

You can find my code above. I am also attaching the screen shot of my maple file.

I would really appreciate if someone could help me out. Thanks for your help.

The following program hangs on the last command and a hard restart is required. The computation of a 2 x 2 matrix times a 2-vector is not that hard. Any ideas as to what is happening?

Another question: if v is a vector that depends on x and y say why does
>solve(v=0,{x,y})
not work?

It should only take a few lines of code to change v=0 to the system {components of v = 0}

Does anyone know if there is a simple way to write a falling factorial (pochhammer symbol) in Maple. It seems pochhammer is the rising factorial with no option to change to falling.

Thanks in advance.

Dears;

Hope everyone is fine. I am try to find the numerical solutions of system of nonlinear algabric equation via newton's raphson method in the attached file but failed. Please see the attachment and try to correct. You can solve it least square method if possible. I am waiting your positive response. 

Help_in_Newton.mw

With my best regards and sincerely.

Muhammad Usman

School of Mathematical Sciences 
Peking University, Beijing, China

Email: muhammadusman@pku.edu.cn

it would be great if you could explain me why maple cant numerically solve this set of 3 ecuatios for h1, h2, k being my unknows terms, it works with an exponential function. there is a way to solve it?

thanks..
 

Download heat_ecuation.mw

Hello! Prompt please as in Maple can determine the distribution function of the resulting histogram distribution? I know about cdf function, but how to act in relation to the histogram do not know.

Histogram:

restart;
with(stats);
with(stats[statplots]);
data2 := [30, 30.5, 31, 31.5, 32, 32.5, 32.6, 33, 33.1, 33.3, 33.6, 34, 35, 36];
histogram(data2, area = count);

In other words, I need smoothing the histogram, get graph and get on it to obtain an analytical expression.

Aslam o Alikum!

Hope everyone going fine with sound health I want to make the graph of following system of ODEs

Eq1 := diff(F(eta), eta, eta, eta, eta)-M*(eta*(diff(F(eta), eta, eta, eta))+3*(diff(F(eta), eta, eta))+(diff(F(eta), eta))*(diff(F(eta), eta, eta))-F(eta)*(diff(F(eta), eta, eta, eta)))-Ha^2*(diff(F(eta), eta, eta));
Eq2 := diff(G(eta), eta, eta)+Pr*M*(F(eta)*(diff(G(eta), eta))-eta*(diff(G(eta), eta)))+Pr*Ec*(diff(F(eta), eta, eta))^2+Nb*(diff(H(eta), eta))+diff(G(eta), eta)+Nt*(diff(G(eta), eta))^2;
Eq3 := diff(H(eta), eta, eta)+M*Sc*(F(eta)*(diff(H(eta), eta))-eta*(diff(H(eta), eta)))+Nt*(diff(F(eta), eta, eta))/Nb;
 

using the BC's

IC1 := F(0) = 0, ((D@@2)(F))(0) = 0, (D(G))(0) = 0, (D(H))(0) = 0;
     F(0) = 0, @@(D, 2)(F)(0) = 0, D(G)(0) = 0, D(H)(0) = 0
IC2 := F(1) = 1, (D(F))(1) = 0, G(1) = 1, H(1) = 1;
 

for Ec := .1; Nt := .1; Nb := .1; Sc := .5; Pr := 10; M := .5; and different values of Ha like Ha:=0, Ha:=2, Ha:=4, Ha:=6 and Ha:=8 in one coordinate. 

I am waiting your positive response.

int(a(t)*b(t)+2*(diff(a(t), t))*(diff(b(t), t)), a(t));
Error, (in int) integration range or variable must be specified in the second argument, got a(t)
 

do not understand this error message,

how to integrate it?

ha := (diff(c(t), t))/(c(t)*(diff(c(t), t))-c(t));
solve(subs(m=ha,f(m))*subs(m=subs(c(t)=a(t),ha)), f(m)) = subs(m=ha+subs(c(t)=a(t),ha), f(m), f);

just expect to find a function ?
 

1. How to generate times series data that have some logic law

but do not include distributive law?

Dear all!

Hope everything going fine with you. I am facing problem to integrate the attached file in this file we need the result of z[1] and others like y[1]. I am waiting your quick answer.

Help.mw

With my best regards and sincerely.

Muhammad Usman

School of Mathematical Sciences 
Peking University, Beijing, China

Email: muhammadusman@pku.edu.cn

Mob #: 0086-13001903838

I have written a C++ program which I feed in an input from Maple which has been converted using the CodeGeneration package in Maple and stored in a text file. For it to be processed in C++ I need to remove the cg = at the start of the Maple output expression. An example of this is as follows:

C(x^2+y^2+z^2);

cg = x * x + y * y + z * z

C++ cannot process the cg= at the start of the string and so I have found ways around it by using Bash or C++ itself to remove or ignore the cg = but I was wondering if it was possible to just not have Maple print it to begin with?

- Yeti

Consider a simple differential equation:

f1 := t -> sin(t);
f2 := t -> cos(t);
dsys := {diff(x(t), t) = x(t)*f1(t)+f2(t), x(0) = 3};
solution_procedure := dsolve(dsys, type = numeric, output = listprocedure);

If initial condition is given like this: x(0)=3, then it compiles. But if I define x(0)=f1(3) then it gives an error:

Error, (in dsolve/numeric/process_input) invalid specification of initial conditions, got HFloat(3.0) = sin(3)

How can I handle this?

rrr.docx

rrr.docx