<div dir="ltr"><div class="gmail_default" style="font-size:small">I think the problem might be with the two calls to generate_sample_indices inside the double do loop.</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">If I'm reading your code correctly, ix and iy will be size 317 and 720 elements respectively.</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">The generate_sample_indices function is actually an NCL function (and not a built-in function) that creates an array of random numbers and then sorts them. This means you are creating two new arrays every time inside this do loop,and never freeing up the space. Also, the sorting may cause the code to slow down.</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">As a start, you might try deleting ix and iy after each iteration in the loop. </div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"><font face="monospace, monospace"><span style="font-size:12.8000001907349px"> do while(i.lt.n)</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> j = 0</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> do while(j.lt.m) ; loop through time</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> ; randomise in space</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> ix = generate_sample_indices( dms(0), 0 )</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> iy = generate_sample_indices( dms(1), 0 )</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> rand_HS(:,:,j) = rand_HS(ix, iy, j)</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> j=j+1</span></font></div><div class="gmail_default" style="font-size:small"><font face="monospace, monospace"><span style="font-size:12.8000001907349px"><br></span></font></div><div class="gmail_default" style="font-size:small"><font face="monospace, monospace"> delete([/ix,iy/])<br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> end do</span></font><br></div><div class="gmail_default" style="font-size:small"><font face="monospace, monospace"><span style="font-size:12.8000001907349px"><br></span></font></div><div class="gmail_default" style="font-size:small"><span style="font-size:12.8000001907349px"><font face="arial, helvetica, sans-serif">You might also consider whether you need to do this every time inside the do loop.</font></span></div><div class="gmail_default" style="font-size:small"><span style="font-size:12.8000001907349px"><font face="arial, helvetica, sans-serif"><br></font></span></div><div class="gmail_default" style="font-size:small"><span style="font-size:12.8000001907349px"><font face="arial, helvetica, sans-serif">Let ncl-talk know if you continue to have problems with this code even after adding the delete command.</font></span></div><div class="gmail_default" style="font-size:small"><span style="font-size:12.8000001907349px"><font face="arial, helvetica, sans-serif"><br></font></span></div><div class="gmail_default" style="font-size:small"><span style="font-size:12.8000001907349px"><font face="arial, helvetica, sans-serif">--Mary</font></span></div><div class="gmail_default" style="font-size:small"><span style="font-size:12.8000001907349px"><font face="arial, helvetica, sans-serif"><br></font></span></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Feb 8, 2015 at 6:25 AM, David Craig <span dir="ltr"><<a href="mailto:dcdavemail@gmail.com" target="_blank">dcdavemail@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
<br>
I have a loop in NCL that randomises an array and preforms some<br>
operations on the result. However, it seems to be using too much memory<br>
and I don't understand why as all variables are preallocated. Does<br>
anyone know what the problem is, code is below.<br>
<br>
thanks,<br>
<br>
David<br>
<br>
<br>
n = 1000<br>
rand_HS = HS_reorder(:,:,1:) ; size 317x720x240<br>
dms = dimsizes(rand_HS)<br>
m = dms(2)<br>
; preallocate array for maximum coefficient values<br>
max_rand_ccr = new(n,float)<br>
i = 0<br>
<br>
do while(i.lt.n)<br>
j = 0<br>
<br>
do while(j.lt.m) ; loop through time<br>
<br>
; randomise in space<br>
ix = generate_sample_indices( dms(0), 0 )<br>
iy = generate_sample_indices( dms(1), 0 )<br>
rand_HS(:,:,j) = rand_HS(ix, iy, j)<br>
<br>
j=j+1<br>
end do<br>
<br>
;calculate max correlation coefficient<br>
max_rand_ccr(i) = max(abs(escorc(data2,rand_HS)))<br>
i=i+1<br>
end do<br>
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