Beefy Boxes and Bandwidth Generously Provided by pair Networks
We don't bite newbies here... much
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

Your analogy doesn't help.

You are constructing a 3-dimensional array, and you are running out of memory. Assuming $data[ 0..X ][ 0..Y ][ 0..Z ];

What we need from you is:

  1. the maximum size of those three dimensions X, Y, Z?
  2. Are the dimensions contiguous or sparse?

    If sparse, the approximate density?

    If one or more of X,Y & Z can run say 3000 .. 4000; or if instead of using every number between 0 ..m; you only use every 10th or 100th; then you can save substantial space by using a hash instead of an array for that dimension of the structure.

  3. Do you need to build the entire dataset before you can calculate your statistics>

    Could you build (say) all of $data[1][Y][Z] for X=1; calculate the stats; and then discard that before building all $data[2][Y][Z] for X=2?

  4. What are you storing in each element of that 3d array?

    Is it just a number? If so, how big will that number get?

    If, for example, each element of the array held an integer < 255, the you can easily substitute a string for the 3 level arrays and save huge amounts of memory.

    Eg. This constructs a 100x100x100 3d array of small integers which requires 33MB of memory.

    @data = map[ map[ map int( rand 256), 0..99 ],0..99 ], 0..99;; print total_size \@data;; 33454784

    This on the other hand construct 100x100x100 2D array of strings. It contains the exact same information, but it only requires 1.6MB:

    @data = map[ map pack( 'C*', map int( rand 256), 0..99 ), 0..99 ], 0.. +99;; print total_size \@data;; 1614784

If you give us the information we ask for, we can almost certainly help you reduce your memory requirements.


With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: Memory issue with cancer data (analogy) by BrowserUk
in thread Memory issue with cancer data (analogy) by ZWcarp

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others studying the Monastery: (7)
    As of 2014-10-24 07:44 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      For retirement, I am banking on:










      Results (130 votes), past polls