Is there a way in Maple to evaluate the following integral - where the "w" are set to go to zero to avoid singularities? B.t.w. Maple just returns the integral unevaluated with or without the "w" with the simple "int" command. 

int(ln(((p1-p3)^2+w^2)/(p1+p3)^(w^2+2))*ln(((p1-p4)^2+w^2)/((p1+p4)^2+w^2))*sin(p1)/(p1*p3*p4), p1 = 0 .. infinity);

or even

int(ln(((p1-p3)^2+w^2)/(p1+p3)^(w^2+2))*ln(((p1-p4)^2+w^2)/((p1+p4)^2+w^2))*sin(p1)/(p1*p3*p4), p1 = 0 .. 100, numeric);

hi

how i can pdsolve these partial differentialequations?

thanks

10.mw
 

Download 10.mw

I have been using CodeTools::Usage with Maple 17 to compare timings of a couple of matrix inversion routines against each other and against the Maple library routines LinearAlgebra::MatrixInverse and LinearAlgebra::Determinant.

The small section of code that I use to collect the cpu times for each method is:

----------------------------------------

udata := Usage(invTest(x,y,z,delta,mu), output=['cputime', 'bytesused'],
              iterations=nRepeats, quiet);
dat[1]:=udata[1]; dat[2]:=udata[2];

----------------------------------------
nRepeats has been set to 25.

In order to get the timings as accurate as possible, I only open a couple of terminal windows on my laptop so as to run the tests with as low a loaded machine as I can get. (I'm running Ubuntu 14.04 on an 8 core Intel (R) Core i7-3840QM, 2.8GHz CPU with 16Gb of memory.)

A test run consists of a sequence of test matrices each of which is run for an increasing sequence of matrix orders. I either time an implementation on its own or I time both an implementation and the Maple library routines. In the later case for each test matrix and order of matrix, I use Usage to first time the Maple routines and then the times for one of the implementations:

----------------------------------------

if compMaple then
udata := Usage(MatrixInverse(A), output=['cputime', 'bytesused'],
              iterations=nRepeats, quiet);
mdat[1]:=udata[1]; mdat[2]:=udata[2];

udata := Usage(Determinant(A), output=[cputime, bytesused],
              iterations=nRepeats, quiet);
mdat[1]:=mdat[1]+udata[1];
mdat[2]:=mdat[2]+udata[2];
else
  mdat[1..2] := 0:
end if:

udata := Usage(invTest(x,y,z,delta,mu), output=['cputime', 'bytesused'],
              iterations=nRepeats, quiet);
dat[1]:=udata[1]; dat[2]:=udata[2];

----------------------------------------

I have noticed the following:

a) If I time both Maple and an implementation, and the same implementation on its own I can get timings that vary up to a factor of 2 or more,

b) Changes in timings for the same test run and as close to the same environment as I can get (i.e., just the two user terminal windows open) can generate timing differences of up to 50%.

c) Sometimes `chaotic' timings are generated, for example,

    n = 150, t = 3 (secs)
    n = 200, t = 24 (secs)
    n = 250, t = 18 (secs)

which cannot be reflecting the times required to perform the calculations. This type of behaviour always seems to occur when the reported memory bytecount is increasing from ~0.25* 10^9 to over 10^9.

Is there anything I can be doing here to get more consistent timings?

I want to use the timings from these tests in a journal article so it would be good to have the same test run under very similar conditions to return timings within a few percent difference of one another. I certainly get this sort of tolerances (<10%) if I use the Fortran cpu_time intrinsic to time Fortran code.

Any advice would be gratefully received.

Using Insert->Table... and inserting information in the cells. 

So I've created Table1 but I can't seem to call any row/column cell information using that name.  How do we do that?  Also, what is the best way to search for information in those cells and return information in adjacent cells? 

Hello,

I have tryed, to run the file ImprovementsInPdsolve.mw with the Mapleversion 2017.3 but in the first example pde[1] I got this error:

Error, (in assuming) when calling 'dsolve'. Received: 'cannot determine if this expression is true or false: not 0 <= -(1/2)*Pi'

 pde[2],  pde[3] and others are o.k. but pde[4] to pde[6] not. Can You give me a hint what's wrong?

With kindly regards

Wolfgang Gellien

Hello all,

I would like to know how to make computations on Quantum Field Theory questions.

For example: to write Feynman diagrams for some interactions, obtain the S matrix of scattering amplitude, then deduce the diffrential cross section.

If anyone is working on these issues in the Maple community, I would be very interested.

Best regards

Jean-Luc Paillet

Hello people in mapleprimes

I asked a question for a similar thing before.
https://www.mapleprimes.com/questions/222751-PDEtoolsdeclare

The question I had then is not solved yet in my mind, so I think  I will ask you
again. It is about differentiation of a composite function.

with(PDEtools):
declare(f(x,y,z),g(t,y));
a:=f(x,y,z);
b:=x=g(t,y);
c:=eval(a,b);
d:=diff(c,y);
OFF;
e:=d;

h:=convert(e,diff);

For both e and d, the notation of D__1 and D__2 appear.
And, even if, with convert, I changed them to another form,
what I can get is more complicated form of h.

Is it inevitable to use D__1 and D__2 brabra in the differentiation of
composite function?

I am writing this question thinking that if there is a way of go around it,
 I want to know.

And, though this is the second question, even if I use latex( ) command,
natually, codes of Tex I can get is that of the output shown on the screen, including D__1 and D__2, even though I want it to be shown with f__x and f__y or that including prime. Then, I have to edit that tex file, changing D__1 to f__x etc. which I think is very complicated modification of the text file.
I wish there is a way to modify it in Maple so as it to be direct TeX codes which  do not require me to modify.
Is it impossible to do such a thing?

Thanks in advance.

diff_2.mw

Maple will multiply two matrices for me perfectly.  

However, when I change the value in one of the cells and try to re-evaluate the product, Maple starts giving me the sum of something in all of my cells.   

Are you simply not allowed to ever change the initial values you set for a matrix?  This doesn't seem to make sense to me.  

I have attached a screen shot to show an example with a random matrix.  

the following code results in an error message: Error, (in forget) lexically scoped parameter out of context

If I click on this error message, it brings me to a page which I visited too often.

if I uncomment the irrelevant minimize command, the error message disappears.

How can I prevent this error without giving irrelevant commands?

kind regards,

Harry Garst

hello...how i can remove this error?

thanks

33.mw
 

Download 33.mw

The following is the PDE I need to solve.

(x*y+1)*(diff(h(x, y), y, y, y))+(x+h(x, y))*(diff(h(x, y), y, y))-(diff(h(x, y), y))^2+k(x, y) = 0, (10.*(x*y+1))*(diff(k(x, y), y,y))+(10.*x+h(x,y))*(diff(k(x, y), y))-(diff(h(x, y), y))*k(x, y) = 0

This is the original boundary condition:

h(0, y) = f(y), h(x, 0) = 0, k(0, y) = g(y), k(x, 0) = 1, k(x, 25) = 0, (D[2](h))(x, 0) = 0, (D[2](h))(x, 25) = 0

After using pdsolve it come out the error:

pdsolve(eval(pde2, P = .1), pdebc4, numeric, [h(x, y), k(x, y)], spacestep = .1)

Error, (in pdsolve/numeric/par_hyp) Incorrect number of initial conditions, expected 0, got 2

If I remove one of the boundary condition when x=0, maybe h(0,y)=f(y), then the error will be this:

Error, (in pdsolve/numeric/par_hyp) Incorrect number of initial conditions, expected 0, got 1

However if I remove both when x=0, it come out this error:

Error, (in pdsolve/numeric) initial/boundary conditions must be defined at one or two points for each independent variable

May I know what is the problem of this equations?

P/S: I know its only differentiate with respect to y and is consider to be an ODE( I need more explantion on this please) and I'm still new to maple. Thanks!!

I downloaded Maple Player, and I don't know how can I use it resolve Maths problems. Kindly, could you explain to me the procedure I shall follow for the reason to use it?

I have been unable to successfully open a text file for writing in MAPLEPLAYER, whether it is requested in the startup code section or via a document tools button.  Is there a way to write to a file in MAPLEPLAYER?  It returns a "no write access" statement.

The write works perfectly in MAPLE 2015.1

MRB

I have created and saved a MAPLE module in an .mla archive. The module contains three procedures A, B, C, where

A calls, B and C.  

Once the module library has been loaded, A acccepts inputs and generates outputs.

Is it possible to create a MAPLE player worksheet which calls the module and share it with a Maple Player (only) user, so that they can then supply the inputs and observe the outputs from A using the Maple Player programme components?

Can anyone help?

MRB

I have downloaded MaplePlayer on my iPad.   I see that it comes with a number of "pre-recorded" programs that it can run.  Is there a way to have it run a Maple worksheet that I have written?   If so, how do I use this app to open an existing worksheet? 

Also, are there any plans for this app on the Android platform any time soon?