Is it considered a bug when pdetest does not give zero for a solution given by pdsolve? 

restart;
pde := x*diff(w(x,y,z),x)+  a*z*diff(w(x,y,z),y)+b*y*diff(w(x,y,z),z)=c:
sol:=pdsolve(pde,w(x,y,z));
pdetest(sol,pde)

Gives

which is not zero.

This is the first time I've seen this happen. 

Maple 2019.1 using Physics version 362

If we have following expression

4*beta*c*lambda^2*mu^2+2*beta*c*lambda*mu^3+2*beta*c*lambda*mu^2*nu+beta*c*mu^3*nu-4*c*lambda^2*mu^2*sigma-2*c*lambda*mu^3*sigma-2*c*lambda*mu^2*nu*sigma-c*mu^3*nu*sigma+4*beta*lambda^3*sigma+4*beta*lambda^2*mu*sigma+2*beta*lambda^2*nu*sigma+2*beta*lambda*mu^2*sigma+2*beta*lambda*mu*nu*sigma+beta*mu^3*sigma+beta*mu^2*nu*sigma+4*lambda^2*mu^2*sigma+2*lambda*mu^3*sigma+2*lambda*mu^2*nu*sigma+mu^3*nu*sigma

If I use the command simplify(---,size), it gives

((2*c-2)*lambda-beta+nu*(-1+c))*mu^3+(2*(lambda*(-1+c)-(1/2)*beta))*(2*lambda+nu)*mu^2-2*beta*lambda*(2*lambda+nu)*mu-2*lambda^2*beta*(2*lambda+nu)

which can also be written if i did manually as

beta*mu^3+(2*lambda+nu)*(beta*mu^2+2*beta*lambda*mu+2*beta*lambda^2+(1-c)*(2*lambda+mu)*mu^2)

My question with all learned people is: in Maple, how i can get most simplified and short expression automaticall?

Please help me to understand the Maple.

Thanking you in anticipation.

I need to use gamma as a "free" symbol in pde that I pass to pdsolve, so that the latex comes out as \gamma OK in the solution.

in other words, the pde itself uses the symbol gamma (as it is written in the textbook and I want to keep it the same). This gamma is not the known constant gamma. Something similar to using alpha and beta or x and y. 

But gamma in a known constant in Maple and I am worried this will affect some computation inside pdsolve if I use gamma  as known number in the PDE (even though I think it should not change the result of pdsolve as there are no other numbers in the PDE input, I just wanted to be safe).

I am not able to clear gamma

unassign(gamma)  gives error since it is protected.

Is  there a way around this? Should I use wrap the name with 'gamma'  or `gamma` for example? 

Here is an example

pde := a*diff(w(x,y,z),x)+ b*diff(w(x,y,z),y)+c*diff(w(x,y,z),z)= alpha*x+beta*y+gamma*z+delta;

It is the gamma above I am worried about using in the input. What is the correct way to do this?  

Hello,

I am trying to work with the Physics package to calculate Christoffel symbols. I have just started using Maple today and am coming up against a few hurdles.

I want to change the signature of the metric from (+---) to (-+++). I am typing the following in math mode:

Setup( signature = '-+++')

However, this is returning the following error:

"Error, invalid sum/difference" with my command rewritten within a red box together with the last '+" within another red box. Can you please help me out with this?

Thank you.

I am completely new to maple and am stuck in the very beginning trying to use the Physics package to calculate Christoffel symbols. Suppose I have coordinates (t, x, sigma, theta). The metric g_ has coefficients that are functions of (t,x,sigma) i.e. the metric is like

g_ = a(t,x,sigma) dt^2 + b(t,x,sigma)dt dx + dx^2 + dsigma^2 + sigma^2 dtheta^2.

(Should I write dsigma^2 or (d sigma)^2?)

How do I tell maple to treat a, b as functions of (t,x,sigma)?

Thank you.

HI, 

Yesterday I replied  denitsastaicova's question while providing an attached file. 

Surprisingly, I wasn't able to save the worksheet after having executed it. The only way I found to save it was to copy-paste it's content in a new worksheet and save this latter without any execution.
Here is the file
events.mw

For info I'm working with  Standard Worksheet Interface, Maple 2015.2, Mac OS X, December 21 2015 Build ID 1097895
on Mac OS Mojave 10.14.3
If I open this file and execute it (and even if I execute only the commands from the initial restart to the three dsolve), I get this pop-up error message when trying to save it:

Does my worksheet contain some undesired character or is it a bug ?

Hello,

How can write a code for determination of Laplacian in a new form is introduced in maple code (First line).

Thank you.

FOR2
 

Download FOR2

I have created a custom port in my MapleSim file and when I try to add the port to a Custom Component I keep getting an error that the connector cannot be found.

The custom port appears in the components pane of my MapleSim model.

I am guessing that I am missing something to fully qualify the port name.

I would like to create a custom component with thermal fluid flow ports but I don't see that type of port as an option in the DAE Custom Component Template.  Can anyone help me with now I would go about doing this?

Maple does not simplify the expression A*[sin(x)]^2+A*[cos(x)]^2=A, where A is any expression.

How can I make it do so? 

Thanks,

Maple 17 64-bit on Windows 8

Hello. How to connect 2 point of segment with animation? I know only one way to do this. We need connect P and Q. We need to create intermediate points like:

for i from 1 to 100
q[i]:=i/100*P+(1-i/100)*Q

It seems to me that this option consumes a lot of resources.

Is there another way to do this with the Maple?
Thanks

I have thought that   D(y)(0)=C1  and  eval(diff(y(t),t),t=0)=C1  mean exactly the same thing which is derivative of y wr.t. "t" evaluated at specific point t=0 is C1.

If you agree they are exactly the same thing, then why dsolve works with both forms used for initial conditions if the option 'series' is not used.

When using the 'series' option, dsolve stops working when using  eval(diff(y(t),t),t=0) form? All else is the same.

ode:=diff(y(t),t$2)+3*diff(y(t),t)+2*y(t)=0;
bc_form_1:=y(0)=C1,eval(diff(y(t),t),t=0)=C2;
bc_form_2:=y(0)=C1,D(y)(0)=C2;
sol1:=dsolve([ode,bc_form_1],y(t));
sol2:=dsolve([ode,bc_form_2],y(t))

Both the above work

But now when I use the 'series' option, the first form stops working!

ode:=diff(y(t),t$2)+3*diff(y(t),t)+2*y(t)=0;
bc_form_1:=y(0)=C1,eval(diff(y(t),t),t=0)=C2;
bc_form_2:=y(0)=C1,D(y)(0)=C2;
sol1:=dsolve([ode,bc_form_1],y(t),'series');
sol2:=dsolve([ode,bc_form_2],y(t),'series')

Is this a bug? 

Just updated to Maple 2019.1  on windows 10.

The code is from the book(SDE). I think P.n := evalm( P.(n-1)&*P0) causes the problem. I have never seen this kind of the structure before ( I did some coding with C and Java). Could you explain that? P0, P1, P2,,,, using for n from 1 to 10. Is "." between P and n the dot (period)? Thank you in advance.

Download TransitionMatix.mw

I have this very ugly ODE system which I solve with "dsolve, numeric, complex=true". It works ok but I'd really like to be able to use events. The problem is that the solution of the system has very small (~10^(-Digits)) imaginary part and as we know "events" works only for real ODEs.

My question is does anyone know a way to force dsolve to solve the ODE as a real system? In Mathematica, there is the function "chop" which does the trick. In Maple, I tried with fnormal and also by forcing some terms to be real but that makes it hit a singularity at 0.01 which doesn't exist when it integrates it as a complex system. In Mathematica, it integrates ok with "chop" without any random singularities. 

I'm currently trying separating the system into real and imaginary parts, but considering how ugly the system is, it may not be so simple (and so far, it doesn't work). So something to trick dsolve would come handy.

Thanks in advance.

How can plot two  and bipolar figures as attached and extract their data.

Thank You.