Re: Octave Memory Exhausted Error Anyone?

[Ben Abbott]

On Nov 5, 2010, at 10:17 PM, William Krekeler wrote:

> Follow up to my post Nov 3 2010 10:12:33 CDT. Since no one responded I’ll 
> rephrase my question.
>  
> Does anyone know a reason why Octave 3.2.4 in Windows can not use more than 
> 1.5 GB of physical memory?
>  
> Bill Krekeler
> 
>  
> From: William Krekeler [mailto:address@hidden 
> Sent: Wednesday, November 03, 2010 10:13 AM
> To: address@hidden
> Subject: Octave Memory Exhausted Error
>  
> I am in the process of testing Octave compatibility of a code set developed 
> in Matlab. The code successfully completes in Matlab 7.8.0.347 (R2009a). 
> Despite having more than enough system memory I am getting the following 
> error in Octave:
> “error: memory exhausted or requested size too large for range of Octave's 
> index type -- trying to return to prompt.”
> Any help determining the source of this error, or a work around, is greatly 
> appreciated.
>  
> Relevant Machine Details:
> Windows XP Pro x64
> 12 GB physical ram
> Octave 3.2.4, pre-compiled install version
>  
> Script Details for Original Failure:
>                 I’ve isolated the code failure to one line, but the error is 
> not specific to this line of code as simplifying the line of code also fails. 
> The original line of code and the simplified test line are as follows:
>  
>       <start code>
> ImageCube = uint16( floor( (ImageCube - 
> minIC).*(single(2^16-1)/(maxIC-minIC)) ) );
> % [ above generates error]
> ImageCube = ImageCube – minIC;
> % [above generates error ]
>       <end code>
>  
>                 Variable and Memory Information is as follows:
>  
>                 ImageCube = 648x480x648 single array using 806215680 bytes (~ 
> 0.8 GB)
>                 minIC = 1x1 single array using 4 bytes
>                 maxIC= 1x1 single array using 4 bytes
>  
>                 At failure Octave is using 828,728 kB (~0.8 GB) of memory, 
> total memory used on system = 3.25 GB, total memory free is roughly 8.6 GB 
> for 12 GB total physical memory.
>  
> Testing:
>                 Following the memory error above and a restart of Octave the 
> following command succeeds. The code below creates a variable whose size is 
> ~1.4 GB using the 1024 definition, at 4 bytes per element of the 376999999 
> element array. Note 377999999 elements fails with the same error. The test 
> code implies two things, first, my original variable does not violate a 
> maximum number of supported elements in an array, second, that my original 
> variable does not violate a maximum memory allowed per variable. Though the 
> test could be saying that Octave is being limited to roughly 1.5 GB of 
> memory, which if the code duplicates an array during the math operations 
> would mean that my original 0.8GB ImageCube variable would become a 1.6GB 
> memory requirement during subtraction of the full array. Failure to perform 
> mathematical operations on the large array is confirmed by the failure of the 
> subtraction operation in the following codeset.
>  
>       <start code>
> Clear all; ImageCube = ones(376999999, 1, ‘single’ );
> % [ above  succeeds ]
> ImageCube = ImageCube – 0;
> % [ above fails ]
>       <end code>
>  
> Any ideas for what could be causing this error or a work around?
>  
>  
> Bill Krekeler

Is your octave built for 64 bits?

I haven't used 64 bit Octave myself. However, my impression is that it remains 
experimental.

Ben