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Hello!

I would like to start with the following set of 9 elements,
A = { E11, E12, E21, E22, E11+E12, E11+E21, E12+E22, E21+E22, E11+E12+E21+E22 }.

I need a procedure that takes each of those elements and creates 3 new ones in the following way: Eij becomes Eij1, Eij2, Eij1+Eij2. So for example, E11 will become: E111, E112, and E111+E112. And for example the fifth element in A (i.e. E11+E12) will become the 3 new elements: E111+E121, E112+E122, and E111+E121 + E112+E122.

Since each of the 9 elements gets triplicated, there will be a new set, call it B, with 27 elements.

B = {E111, E112, E111+E112, E121, E122, E121+E122, ... }

Now I want to repeat this process of triplicating again so that, for example, E111 becomes: E1111, E1112, and E1111+E1112. And so on. This new set C will have 81 elements. Now I want to repeat this one last time. The final set, D, will have 243 (3^5) elements. 

Step 2: 

For every pair of elements x and y in D, I want to compute z:=(x+y)mod2. If z already belongs to D, discard it, otherwise, place z in the set D2. Do this until there are no more elements to add together (note that if x+y is computed then I don't want y+x to be computed also--that's inefficient). Maybe the most efficient way is to perform all possibly combinations of x+y mod 2 to create the set D2 and then just go: D2 setminus D.

Step 3: For x in D and y in D2 perform all possible combinations of z:=(x+y)mod2 and place these in D3 then perform set subtraction again: D3 minus D2 minus D.

Repeat this process again: x in D and y in D3 to create new elements in D4. Repeat again until Dm is empty (that is, D(m-1) will be the last set that contains new elements). I'm expecting around 12 sets... 

The issue with this whole algorithm is that I often run out of memory so I need a clever way to do this, since this algorithm is essentially classifying 2^32 elements into disjoint sets. Thank you! 

Hi,

 

  I have a loop code, such as

 

****

i_max:=10;

for i from 1 to i_max do
  blah blah blah

end do;

****

 

  I would like to clean memory, something like restart suppose to do, after each cycle. Restart could only work at top level. How should I do to clean memory after each cycle?

 

Hello everybody,

 

I have to solve a non linear equation using a numerical method. I use a loop after each iteration, Maple keep the results in memory instead of release their in variable. So calculation time is very long and the memory goes up.

Could you help me to improve the calculation time ? In fact, I would like to store results in a list and maple erases each intermediate results.

 

Thank a lot

 

 

[carré]NewmarkAlgo2FCzAlp.mw

Hi,

I have a code which stores large amount of intermediate data.

Ones the data has been used i unassign the variables storing the data and perform garbage collection. But memory is not returned to the operating system for reallocation.

can somebody please tell me how to release memory back to os so that task manager shows memory release (without doing the maple server reset).

And i dont understand the purpose of stupid gc if it is not returning memory back to the windows?

Hi Mapleprimers,

I was wondering if there way a way to use restart(); and clear Maple's memory, but protect the memory in a certain variable?  I would like to return the memory to the operating system, but keep a symholic function in memory.

Alternatively, is there a way to save a symbolic function to a file, then reload it at a seperate time?

 

I'm running a long loop with a lot of variables. I have noticed that Maple does not seem to clear its memory after each loop iteration, which results in very large memory used after all the iterations. I can't use restart because I need a few variables to be remembered throughout the loop for analysis afterwards. So the question is how to clear the memory for selective variables and procedures at the end of each iteration.

I've found the following project: http://www.parallella.org/

It is a very cheap but impressive computer ( 64-cores, they say it gives about 90 GFLOPS of computing power). The problem is the very limited amount of memory (1GB). See: http://www.parallella.org/board/ for specifications.

Now my question is: do you think Maple will run on this machine (acoording to the site it will run Ubuntu) and if so then does it make sense to try it given the small amount of memory it has? Or in another words: do there exist problems that could be solved by Maple on this powerful machine and that cannot be solved on a regular machine with let's say 4GB of RAM?

Hi,

I need to solve following problem, but i m facing memory allocation problem in code. I dont know where memory is consuming.

Download nonlinearx.mw

Thanx in advance.

Regards

Sunit

 I have a system of 4 rational equations involving 6 variables. I want to solve this system for 4 variables. 


Whenver I try to do this I get either an error message about solutions being lost, or maple being unable to allocate enough memory.

The Commands involved are here: 

 

Hi,

     Seems like a silly questionm but the Maple help page suggested usign the option 'interpolation=false' for a numeric dsolve since I ran out of memory (I'm solving a huge matrix DE). But that's not an option in the command dsolve, has this been removed as of Maple 16? Or any suggestions on using less memory? I have 16Gb RAM, 

 

Thanks

I often have to create density plots with many (thousands of) points. Hence the first thing I do when I install a new version of maple on linux, is edit dir_of_maple/bin/maple so that

JAVAHEAP=512

is instead

JAVAHEAP=4096

I have done this for years and never have any memory problems. But recently I have sent my code to someone who runs Windows and they seem to have "out of memory" issues when trying to do density plots of large datasets.

Hello,

I've written a code that I'd ultimately like to process in parallel over a grid of parameters, but before I can even think of doing that, I need to find a workaround for the memory allocation issues I'm having. Probably due to the way that it's written, Maple's built in garbage collection isn't working very well (if at all), and the code allocates another 100 MB or so every 10,000 iterations. Even if I content myself with running it for say 200,000 iterations,...

I am trying to solve a square polynomial system (16 x 16, I was able to solve an 8 x 8 fine) using the package RegularChains (with Groebner bases the problem is the same) but I have a memory constraint of 4G in the Linux cluster and my batch job gets terminated after Maple grabs too much memory:

TERM_MEMLIMIT; (job*killed*after*reaching*LSF*memory*usage*limit.Exited, with, true)*(File*size*limit*exceeded.Resource, usage, true)*summary; CPU*time;(4509.00*sec.Max, Memory, true...

Dear Friends.   I solve a group of linear equations and the memory is not enough and i can't 
adding a new hardware to the computer.

i increase the virtual memory of the computer from some chose for the operating system 
but it seem to me the Maple use the memory from the hardware only.

I want to know is there any method to make the Maple using the virtual memory for 
the computer

Amr

Hi,

 

is there any analogous command to whos in Matlab to list the memory usage of specific variables in workspace?

Thanks!

Bye

Tom

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