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Re: negative FileByteCount

  • To: mathgroup at smc.vnet.net
  • Subject: [mg83081] Re: negative FileByteCount
  • From: David Bailey <dave at Remove_Thisdbailey.co.uk>
  • Date: Sat, 10 Nov 2007 03:38:09 -0500 (EST)
  • References: <fh1c35$boh$1@smc.vnet.net>

rych wrote:
> Is there a maximum file size permitted in Mathematica? Because it
> seems I can't work with my 3GB file,
> In[1]:= FileByteCount["scandata.xyz"]
> Out[1]= -936210076
> 
> snum = OpenRead["scandata.xyz"]
> Read[snum, Number]
> Out[]=EndOfFile
> 
> If not Mathematica, where should I bring files big like this (which
> are xyz point cloud data, need to denoise/detrend, perhaps via a
> wavelet decomposition or other multiresolution analysis)
> 
> 
That is obviously a bug - I presume the calculation is done internally 
with a 32-bit integer. I suggest you report it to Wolfram support.

The limit is almost certainly 2^31-1 (the largest 32-bit integer), so if 
you can accommodate that size my guess is that you will be OK, failing 
that you could read the data in via Java using the J/Link package.


David Bailey
http://www.dbaileyconsultancy.co.uk


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