z = peaks ();
h = meshz (z(20:30, 20:30));
print -dpng tst.png
cdat = get (h, 'cdata');
cdat(1:5, 1:5)

ans =

    1.8168    1.8168    1.8168    1.8168    1.8168
    1.8168    1.8168    1.8168    1.8168    1.8168
    1.8168    1.8168    3.4790    3.7573    3.6990
    1.8168    1.8168    3.1565    3.5507    3.6013
    1.8168    1.8168    2.6313    3.1121    3.2505

zdat = get (h, 'zdata');
zdat(1:5, 1:5)

ans =

   -0.1237   -0.1237   -0.1237   -0.1237   -0.1237
   -0.1237   -0.1237    3.4790    3.7573    3.6990
   -0.1237    3.4790    3.4790    3.7573    3.6990
   -0.1237    3.1565    3.1565    3.5507    3.6013
   -0.1237    2.6313    2.6313    3.1121    3.2505

xdat = get (h, 'xdata');
xdat(1:5, 1:5)

ans =

     0     0     0     1     2
     0     0     0     1     2
     0     0     0     1     2
     0     0     0     1     2
     0     0     0     1     2

ydat = get (h, 'ydata');
ydat(1:5, 1:5)

ans =

     0     0     0     0     0
     0     0     0     0     0
     0     0     0     0     0
     1     1     1     1     1
     2     2     2     2     2

diary off