MATLAB using too much RAM

I am having a problem with MATLAB regarding RAM usage. I am trying to run a function (code below) and every time I plot the function using surf my RAM usage spikes up to an absurd amount causing the system to write to the hard drive drastically slowing down system performance. My questions is if there is anyway I can reduce the RAM usage. I am new to MATLAB so if the answer is obvious I apologize for my ignorance. I am running MATLAB 2014a on Mac OS X with 16gb of 1600Mz DDR3 Memory.

x=randn(1,10000);
a=sort(x);
y=x;
b=sort(y);
[X,Y]=meshgrid(a,b);
z=(1000/sqrt(2*pi).*exp(-(X.^2/2)-(Y.^2/2)));
subplot(2,2,1)
surf(X,Y,z);
shading interp
axis tight
colormap cool
subplot(2,2,2)
surf(X,Y,z);
shading interp

Thanks in advance for the help.

Answer 1

[per isakson]

On R2013b (64bit Windows7 32GB) your script run without error. It increased memory usage, according to the task manager, from 5.6 to 21.1 GB. See screen clip below.

I cannot see there is much the user can do about that. Did you try single precision? However, do you really need the large matrices

    >> whos X Y 
      Name          Size                   Bytes  Class     Attributes
      X         10000x10000            800000000  double              
      Y         10000x10000            800000000  double

I replaced

    x=randn(1,10000);

by

    x=randn(1,1000);

The script run in no time, the increase in memory usage was hardly visible and I cannot see any difference in the result on screen.

&nbsp

[Desmond Johnson]

Thank you so much for the help unfortunately I do need those exact numbers because it is for a homework assignment for my engineering class. I have already informed my professor of the resource issue this code causes so hopefully he will modify the numbers we need.