array exceeds maximum array size preference

i had this error :

Requested 65536x65536 (32.0GB) array exceeds maximum array size preference. Creation of arrays greater than this

limit may take a long time and cause MATLAB to become unresponsive. See array size limit or preference panel for

more information.

AT LIGNE n°3:

1. s_old = s;
2. s = [s(N*M-L+1:N*M);s];
3. EYE_MAT = eye(length(s_old));
4. PI_mat = [EYE_MAT(:, 2:end) EYE_MAT(:, 1)];

can some one help me pllllz !

[Torsten]

What kind of help do you expect from us ?

Either reduce the size of your problem or buy more RAM for your computer.

[Steven Lord]

Without knowing what you're trying to do, it's going to be difficult or impossible to offer any concrete guidance for how to avoid the array size preference limit. You could turn off the preference, but as the message says trying to create a really large matrix may take a LONG time (or may not be possible on your machine at the moment.)

If you tell us (in words not code) what your ultimate goal is with this s array we may be able to suggest an alternate approach that avoids creating a huge matrix. Don't assume we know anything about the problem you're trying to solve; start from the beginning.

[amani]

the code is about output of modulation for wireless channel and noise

[Steven Lord]

Please provide more detail. What you'd told us is like telling your mechanic "My car makes a funny noise when I drive it." That could be something minor (one of your bumper stickers is slightly loose and is flapping around) or it could indicate your engine is about to seize up and require complete replacement. The fixes for those two issues are obviously quite different!

[amani]

L = max(delay_taps);

s_old = s;

s = [s(N*M-L+1:N*M);s]; %add one cp

s_chan = 0;

le = length(s_old);

EYE_MAT = eye(the);

These are parameters of the dopler effect of a noisy transmission channel. Then I fixed the maximum length of this effect after we position the matrix s then we produce an EYE_MAT mastery from matrix s. and I had this problem. I hope you understand better now. what can i do plz ( add parmtr, ...) ?

[Torsten]

If you have a PC with 16 GB RAM and the eye array alone needs 32 GB, shouldn't this tell you that you have to reduce the problem size or buy a new PC ?

[amani]

thank you @Torsten i am sur now that the problem about my PC. yes it has 16GB RAM. thank you

Answer 1

[Mann Baidi]

Hi @amani,

I observer that you are trying to create a 65536x65536 matrix in your script. You are getting the error due the maximum array size limitations in MATLAB. You can try removing the limitations for the maximum array size by unchecking the maximum array size limit checkbox from the preference panel following this path.

MATLAB >Preferences > Workspace > MATLAB array size limit.

[amani]

waaaaaaaaaaaaaaaw thank you @Mann Baidi really thank you ! i make don't limit the maximum array size to a percentage of RAM , BUT I STYLE HAVE THIS PROBLEM :(

[amani]

this is the propriety of my laptop :

[Mann Baidi]

You can refer to the following link for some other possible workarounds:

https://www.mathworks.com/help/matlab/matlab_prog/resolving-out-of-memory-errors.html

I would suggest to try 'tall' arrays

https://www.mathworks.com/help/matlab/matlab_prog/resolving-out-of-memory-errors.html#mw_a52e9140-fab7-4734-994d-3995bb8bb231

[amani]

now i have a new erreur at other ligne ! it seen that the first problem it is done .... yet this now it is about the memory too ... how you can see it @Mann Baidi ?