| Trouble writing very large files [message #64729] |
Thu, 15 January 2009 12:39  |
wlandsman
Messages: 743
Registered: June 2000
|
Senior Member |
|
|
Vince Hradil posted a message in September about problems writing
large files. I am encountering the same problem, but with a
variation. Instead of giving a segmentation fault, IDL returns
without writing anything.
IDL> print,!version
{ x86_64 linux unix linux 7.0 Oct 25 2007 64 64}
IDL> im = intarr(4096,4096,256)
IDL> openw,1,'test.dat'
IDL> writeu,1,im
IDL> close,1
IDL> $ls -l test.dat
-rw-r--r-- 1 wlandsma shadow 0 2009-01-15 15:22 test.dat
If I instead do the same thing with a 4096 x 4096 x 255 array, then
IDL does crash with a segmentation fault. My guess is that an
internal IDL counter is not properly defined as 64 bit integer, and
so is being set to zero in my first case (where subscripts are a exact
multiple of two). In the second case it is being set to a negative
number and causing IDL to crash.
In any case this seems to be an internal IDL bug, since I should be
able to write these arrays on a 64 bit machine. --Wayne
|
|
|
|
| Re: Trouble writing very large files [message #64819 is a reply to message #64729] |
Fri, 16 January 2009 00:35  |
Bringfried Stecklum
Messages: 75
Registered: January 1996
|
Member |
|
|
wlandsman wrote:
> Vince Hradil posted a message in September about problems writing
> large files. I am encountering the same problem, but with a
> variation. Instead of giving a segmentation fault, IDL returns
> without writing anything.
>
> IDL> print,!version
> { x86_64 linux unix linux 7.0 Oct 25 2007 64 64}
> IDL> im = intarr(4096,4096,256)
> IDL> openw,1,'test.dat'
> IDL> writeu,1,im
> IDL> close,1
> IDL> $ls -l test.dat
> -rw-r--r-- 1 wlandsma shadow 0 2009-01-15 15:22 test.dat
>
> If I instead do the same thing with a 4096 x 4096 x 255 array, then
> IDL does crash with a segmentation fault. My guess is that an
> internal IDL counter is not properly defined as 64 bit integer, and
> so is being set to zero in my first case (where subscripts are a exact
> multiple of two). In the second case it is being set to a negative
> number and causing IDL to crash.
>
> In any case this seems to be an internal IDL bug, since I should be
> able to write these arrays on a 64 bit machine. --Wayne
It seems to be a writeu bug since save works fine
IDL Version 6.4 (linux x86_64 m64). (c) 2007, ITT Visual Information Solutions
Installation number: 12207.
Licensed for use by: TLS Tautenburg
IDL> hhh=intarr(4096,4096,128)
IDL> openw,1,'hhh'
IDL> writeu,1,hhh
Segmentation fault
2nd attempt
IDL> hhh=intarr(4096,4096,128)
IDL> save,hhh,file='hhh'
IDL> exit
Regards,
Bringfried
|
|
|
|
| Re: Trouble writing very large files [message #64820 is a reply to message #64729] |
Thu, 15 January 2009 19:35 |
Andrew Cool
Messages: 219
Registered: January 1996
|
Senior Member |
|
|
On Jan 16, 6:39 am, wlandsman <wlands...@gmail.com> wrote:
> Vince Hradil posted a message in September about problems writing
> large files. I am encountering the same problem, but with a
> variation. Instead of giving a segmentation fault, IDL returns
> without writing anything.
>
> IDL> print,!version
> { x86_64 linux unix linux 7.0 Oct 25 2007 64 64}
> IDL> im = intarr(4096,4096,256)
> IDL> openw,1,'test.dat'
> IDL> writeu,1,im
> IDL> close,1
> IDL> $ls -l test.dat
> -rw-r--r-- 1 wlandsma shadow 0 2009-01-15 15:22 test.dat
>
> If I instead do the same thing with a 4096 x 4096 x 255 array, then
> IDL does crash with a segmentation fault. My guess is that an
> internal IDL counter is not properly defined as 64 bit integer, and
> so is being set to zero in my first case (where subscripts are a exact
> multiple of two). In the second case it is being set to a negative
> number and causing IDL to crash.
>
> In any case this seems to be an internal IDL bug, since I should be
> able to write these arrays on a 64 bit machine. --Wayne
Wayne,
A similarly interesting response at the command line ;-
IDL Version 6.4, Microsoft Windows (Win32 x86 m32). (c) 2007, ITT
Visual Information Solutions
Installation number: 100512.
Licensed for use by: Surv Systems Div, DSTO
IDL> print,4096L*4096L*256L
0
IDL> print,4096L*4096L*255L
-16777216
And that's 32 bit Win.
Andrew
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
