with(PDEtools);
pde := diff(c(x, t), x, x) - h*diff(c(x, t), x) = diff(c(x, t), t):

iv := c(0, t) = 0, c(a, t) = 0, c(x, 0) = c0:

de := pdsolve([pde, iv], c(x, t), build);

                         de := ( )

Does anyone know how to solve this PDE?
Thank you,

Oliveira

Is there any way to place a command to the right of an expression to perform a task? Because I only know the way that puts the command to the right.A simple example:

w1 := simplify(sin(x)² + cos(x)²);

                       w1:=1

w2:=sin(x)²+cos(x)²:-simplify;
             Error, invalid module reference

I wonder if there is a way to put the commands, also to the right of the expressions, as above.

Thank you,

Oliveira
   

Hi,

I seeking for informations on the Statistics:-ChiSquareSuitableModelTest procedure:

1. Once you have choose the number of bins, what strategy does this procedure use to define the bins (equal width, equal probability, other one?).
    
2. It seems the procedure accepts any value for this number of bins and that its correct use then is under the sole responsability of the user. Am I right?

In the book below (but I'm sure this can also be found on the web) there is a detailed discussion concerning "good practices" in using the Chi-Square goodness of fit test: does anyone known is something comparable is used in ChiSquareSuitableModelTest ?

Statistical methods in experimental physics, W.T.Eadie, D. Drijard, F.F.James, M. Roos, B. Sadoulet
North-Holland 1971
Paragraph 11.2.3 "choosing optimal bin size"


Thanks in advance

Hi. I want to get a Fourier transform under the equation How to do this? Equation_is.docx

Greetings!

I am trying to solve a system of equations involving several symbols. The answer I am getting involves rootof...
I have tried to fix it, and read several post on MP, but in vain. Please help me to get a solution which does not involve root of solutions. Coz the paper I am follwing has a very elegant solution to these equations which i am failed to obtain via maple.rootof.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/rootof.mw .
 

Download rootof.mw

Most of the time, odetest() returns just zero if solution satisfies ode, and non-zero expression if solution does not satisfy ode.

So I was just checking for zero as return value to check if my solution was verified or not. This works for most cases.

But there are cases when odetest returns odetest/PIECEWISE` where some cases are zero and some are not.  Example is below.

For this, I still want to consider my solution as valid if one of the cases in piecwise is zero. But I am not sure what is a robust way to do this in code. Currently, I do the following

restart;
ode:=x*diff(y(x),x) = y(x)+2*(x*y(x))^(1/2);
my_sol:=y(x)=x*(ln(x/_C1)^2 - 1) - 2*(-1 + sqrt(ln(x/_C1)^2))*x;
res:=odetest(my_sol,ode);
if res<>0 then
   if type(res,'function') then #this meant to handle PIECWISE                      
      print("verified");
   else
      print("did not verify");
   fi;
else #if we come here, res=0, so I am sure it is valid.
   print("verified");
fi;

In the above, the check  type(res,'function')  is meant to catch PIECEWISE  return, since when I did type(res) Maple told me the type is function.

But I am not sure if this is a robust way to check for this, as it might be possible maple will return non zero, and also a function, but it will not be what I think it is (i.e. PIECEWISE) and then I would flag my solution as valid when it is not.

worksheet attached also.

Download how_to_check_odetest.mw

Download badSums2.mw

Hello. It is required to find a solution of the boundary value problem by cubic b-spline collocation

We are looking for a solution in the form of a spline S(x). A cubic spline S(x) is represented as an expansion over normalized B-splines

Perhaps someone familiar with the method and can help implement the solution on Maple? I agree to any kind of cooperation. Really need help

Dears,

I have this file (of course it's not the real file):

input parameters
A := 5;
B := 6;
C := 7;

derived parameters
E := A*B;
F := cos(A)+e^B;
G := 265/C;
Parameters to be calculated
T := E^2+G-sin(F);
U := F+E-B;

I'd like to find a way for changing A, B, and C (for example giving them the values 1, 2, .. ,9) and getting a table (i mean a CSV or something else) with the values of T and U calculated for the different input values.

Do you know if it is possible?

And sorry if I wrote something wrong, it's my first post, and I'm not expert with Maple. I used it many years ago at the University, and now I'm trying to use it again.

I can type expression below:

s1 := sqrt(2);
                              (1/2)
                             2     
map(op, indets(s1, sqrt));
                             /   1\ 
                            { 2, - }
                             \   2/ 
s2 := log[2](3);
                             ln(3)
                             -----
                             ln(2)
map(op, indets(s2, ln));

And expression above is error
Error, type `ln` does not exist

Can you help me?

s3:=surd(2,3);

map(op, indets(s3, surd)); --> { } 

Download help_map_indets.mw

I want to solve the equation (-2*cos(x)^2+2*sin(x+(1/4)*Pi)^2-1)/sqrt(-x^2+4*x) = 0 in RealDomain. I tried
 

restart; 
RealDomain:-solve({(-2*cos(x)^2+2*sin(x+(1/4)*Pi)^2-1)/sqrt(-x^2+4*x) = 0}, {x});

I got four solutions

If I work around

restart;
 RealDomain:-solve({-x^2+4*x > 0, (-2*cos(x)^2+2*sin(x+(1/4)*Pi)^2-1)/sqrt(-x^2+4*x) = 0}, x);

I only got two solutions

With Mathematica, I got three solutions 

That is mean, Maple lost the solution x = 5*Pi/4. I check this thing

f:= x-> (-2*cos(x)^2+2*sin(x+(1/4)*Pi)^2-1)/sqrt(4*x-x^2) ;
f(5*Pi/4);

and got the result 0. 

Are these bugs?

Dear all

I would like to find the optimal parameters of the attached optimal control problem 

The system of ODEs is defined and boundary conditions and The hamilton Jacobi Bellman equations is written.

Optimal_control.mw

Many thinks

I'm currently working my thesis and can someone help me to write a code to solve this IVP

u_t + 2×u²×u_x−(u_x)²−½×u_{xx}×u=0

with initial condition

u(x,0)=-tanh(x)

Dear friends,

Greetings.

How to get the second solution.

how to change the guess value in maple.

figure 1 plot in Matlab with two different initial guesses.

TWOSOLUTION.mw

I am writing a maths books using maple now. It is fantastic to use maple for writing books in maths.
 

Download cannotCopyWhy.mw

I enclose a part of my document where in I made a particular line with text and maths formats combined.Then I made changes in the line. Now copy paste does work only for the later half (both text and maths formats). The corrected first part is not being copied.

How do I do the corrections properly so that copy paste is not a problem at laer stages.

Thanks for the answer.

Ramakrishnan V