Hi,

  Suppose I have an array

A[1]:=a;

A[2]:=b;

A[3]:=c;

  I would like to check if an element, e.g. "c", belong to this array. I can contrsuct a "for... end do" command to compare each element and/or construct a subroutine. 

  Is there any build-in function in maple can do that? Perferably return true/false

Thank you!

I want to compute the following solve:

C:=A, B, F, H(It has 4 unknowns):

V:=R,Y,E,I (It has 4 equations):

solve({V},{C});

By hand calculations I just found that the solve result is real ,but in maple there is no solution and no error (the maple ignores to solve this equation !!!) 

can anybody help me to find the solve soltuion ?

Thank you 

H. Kabir

hi.I want to dsolve set of nonlinear equations with one unknown parameter ...is this possible with dsolve rule.in matlab this possible with bvp4c rule..please help me for this problem.if we should another rule please attached file reform.Thanks alot12.mw

I need to solve a set of equations but changing a constant each time.

For example, x+by=0, bx-y=10 where b=10,20.

I don't want to put it in a loop because, in loop, the equations are solved repeatedly. I want Maple to solve it only once and substitute b values automatically since I want to solve big set of equations faster.

Is there any option in Maple to do so with a single command

I know how we can add a member to a mathematical set ,for example :

C := NULL;

C := C, V, B, X;

print(C)

V, B, X

but, my problem is that how we can subtract a member from the defined set ?

Thanks,

hi.how i can chose a minimum and positive answer of different answer in solve rule...

my program attached below.for example at this , the second answer should be selected as 1.965392881*10^9 ,that is the minimum and posetive among other...

thanks alot

11.mw

Dear all,

I am trying to solve the following partial differential equation (transport or advection equation) with given initial and boundary conditions:

restart: with(PDEtools):
sys := [v*diff(u(x,t), x) + diff(u(x,t), t) = 0, u(x,0) = exp(-x), u(0,t) = sin(t)];
pdsolve(sys);

But it does not work. The solution is (or should be): 

u(x, t) = exp(t*v-x)+Heaviside(t-x/v)*(sin(t-x/v)-exp(t*v-x))

I think the reason is that the interval for t (in [0, inf)) and x (in [0, 1]) is not specified. On the other hand, this works:

restart: with(PDEtools):
sys := [diff(u(x, t), t) = diff(u(x, t), x, x), u(0, t) = 0, u(1, t) = 0, u(x,0) = f(x)];
sol := pdsolve(sys);

How can I solve a PDE like the transport equation with given initial AND boundary conditions?

Thanks a lot

I want to display calculation steps by maple like this

k=a+b*c=2+4*4=9

How can I do so that when I enter k:=a+b*c (the value of a,b,c have been assigned) and it can show the substitution process and display the result like this

The font size in the output pane of the standard interface, interactive debugger is really, really small and I can't figure out how to increase it. (Other than drop my screen resolution from its native 2560x1440, which makes it bigger but "fuzzier" - not a huge improvement for tired eyes!!)

I started to notice strange things happening to Maple help pages lately when I google something. I think someone is changing them from inside Maplesoft? Now they look hard to read since I see text below another text and also can't copy it to retype it in my notebook since the syntax is not even valid. Here is a screen shot

http://www.maplesoft.com/support/help/maple/view.aspx?path=FileTools%2fText%2fOpen

I thought at first my browser was playing games on me. But I tried it with firefox and Chrome and after refreshing, and the pages still look mangled like the above.

Since I find it hard to believe someone at Maplesoft will make help pages like the above on purpose, where text falls below the line and it not even possible to interpret it when one wants to copy it, since the syntax is not even valid Maple syntax, I would have to imagine there is a bug somewhere inthe help pages generation.  But if so, someone must have seen it before me. I can't be the only person in the world who is googling Maple help.

This is why I am asking.

Is everyone seeing the same thing I am seeing? I am on windows 7, using Latest browsers.

I do not understand why I am getting permission denied trying to create a file.

restart;
fd := FileTools[Text][Open]("C:\\foo.txt", create=true,overwrite=true);

     Error, (in FileTools:-Text:-Open) permission denied

I am running the above on my PC, from Maple, using the same user which is me. I can ofcourse create a file on my C drive outside of Maple. So I do not understand why it says permission denied. Also tried "C:/foo.txt". Also tried

         fd := FileTools[Text][Open]("C:\\foo.txt", create,overwrite);

Any idea what can be the problem? and how to determine why it is giving this error? I am on windows 7, using Maple 2015.

http://www.maplesoft.com/support/help/maple/view.aspx?path=FileTools%2fText%2fOpen

http://www.maplesoft.com/support/help/maple/view.aspx?path=IO_errors

"permission denied" - An attempt was made to read from a file on which the user does not have
read permissions, or write to a file on which the user does not have write permissions."

Well, I do have write permission to make a file on my C drive !

I tried using fopen, and got same error

restart;
  try     
     fd := fopen("C:\\foo.txt",APPEND,TEXT);
  catch:
     print(`Unable to open file, error is`);
     print(StringTools:-FormatMessage(lastexception[2]));
  end try:

                 Unable to open file, error is
                      "permission denied"

So I have no idea why I keep getting permission denied.

plz help me, I m trying to solve homotopy analysis method for lane emden, what additional steps I have to taken in above programming?

Download LE_EQ.mw

Hi,

  Excuse me, I have the following code

###########################

with(combinat);
with(LinearAlgebra);
f:=([1,2,3]);
permute(f);

n:=3;
g:=array(1..n);

for i from 1 to n do
  g[i]:=i;
end do;

permute(g);

###########################

 The output ends up with

Error, (in combinat:-permute) 1st argument must be a list, set or a non-negative integer

 It seems that maple will not generate permutation of g... How to generate the permutation of array g? i.e. by assigning all variables automatically.

Thank you very much!

Hi, 

     I was just curious about the difference between defining tensors as arrays/matricies/TensorArrays vs defining them as algebraic symbols. I found that defining them as an expression lead to the wrong answer, and I was forced to define a tensor (LKh) as an array. I've attached a worksheet demonstrating my problem.

I apologize for the amount of tensors needed to find this problem, but it is the only one I have reproduced the issue. I basically define the metric
Metric = g_
auxillary tensor = h
Killing vector = K
LieDerivative of h, wrt K = LKh (not a tensor array)
LieDerivative of h, wrt K = LKh2 (tensor array)
Then I compare two expressions, rho1 and rho2 computed from LKh and LKh2 and they disagree. 

MapleQuestion.mw

Thanks!

I ran into a problem mentioned here before: With lots of code in one execution group, the standard GUI editor becomes very slow at least in older versions of Maple (I have reason to believe that this is mostly fixed in Maple 17 and, presumably, newer). With one of my packages this has become enough of a problem to force me to deal with it (and Modules and Packages have to be all in one execution group). I have some machines that cannot go beyond Maple 15 so I keep my stuff compatible with it (so far not a big sacrifice).

The fix is rather easy: In the GUI, export the code as "Maple Input" which creates a file with extension .mpl. Then, in the GUI have a small file that uses "read" to read-in and execute the code (of the module). In my case, I have the necessary LibTools statement to save as a .mla right after the package code ends so, bingo, I have just updated the package. I edit the .mpl file in Emacs.

So I installed Joe Riel's Emacs mode maplev-mode.el. This works rather well. However, it took not long for it to show its age: it does not recognize the multi-line comments (*...*). This is kind-of bad as this forces me to not use quotes in the comments since they mess-up the keyword highlighting esp. when using single quotes as in "I'll" and so on. Likewise, maplev-indent-buffer messes up the whole buffer as it interprets the multiline comments as code.

So my question is: is someone still working on this and using it?? I guess I can work around some of these things, but it would be nice if this worked.

Incidentally, my version of maplev-mode.el seems to be dated June 2005.

I know Joe is here on occasion, maybe he can chime in. It is not absolutely fatal; I could forgo using maplev, but if I am forced to go this route of readin in the package; using maplev-mode at least gives me something in return. Unfortunately my elisp skills are not quite up to fixing this myself; at least not in a reasonable time.

If it is relevant: I use Emacs 22.1 on Mac OS X. Yes, I could upgrade to at least Emace 23.4, if that were the issue.

Thanks in advance,

Mac Dude