Error using ==> mupadmex Error in MuPAD command: Out of memory?

Dear all

I have this error shown

the memory used seem to be very little.Please help!!!!!

please help!!! thank you very much.

Answer 1

[Walter Roberson]

Symbolic solutions of larger matrices are inherently large. For example the inverse of a 5 x 5 matrix is over 200000 characters long, and 6 x 6 is over 2000000 long; each additional increment makes the inverse about 10 times larger to represent on output -- and additional memory might be required during the calculation. Multiple gigabytes to calculate the 7 x 7. Roughly 2.2 * 10^N is the output size for the symbolic inverse of a matrix N x N.

If you do not have that much memory, then either add physical memory or add "swap" (which will likely be very slow unless you are using solid state disks).

There is no "compact" or "memory efficient" symbolic inverse. Symbolic solutions are exact solutions and every portion of the solution is needed to get the right answer. You might be able to simplify() afterwards but the sizes I list above are after simplification.

What size of matrix are you trying to process?

[chan trea]

thank you very much sir,, now I am solving the 20x20 matrix, but my objective is ,, can solve as large as possible..

I am very appreciated for you answer. best regard!!

[Walter Roberson]

My estimate would be that it would take approximately 2.1 * 10^20 characters to represent the final symbolic determinant of a 20x20 matrix, plus an unknown amount of working memory. 2.1E20. It would not surprise me if close to 1 zettabyte of memory was required. That would require at least 67 bits of address space. Current implementations of the x64 processor support only 48 bits of address space, roughly 2.8E14 bytes, so you would need somewhere on the order of 750000 such systems completely filled with memory.

The largest matrix that my system was able to take the symbolic matrix of is 6 x 6. I think you have more memory than me so I think you could probably do 7 x 7, but I doubt you could do 8 x 8.

[chan trea]

thank you very much, I will try it. Best regard!!