[Octave-patch-tracker] [patch #7668] Enhancement, speedup of loading partial data from a hdf5 file

[anonymous]

Follow-up Comment #2, patch #7668 (project octave):

I've attached two small scripts, the first creates a hdf5 file.
Thought that was the easiest way to provide a large file with similar tree
structure as the ones I work with.
The second script will perform simple measurements. The file is first loaded
into memory and then read again and then some data is read partially.

This is to try and get rid of latency loading stuff from disk and be fair.

Note, the second script uses clear so make sure you don't have anything
important in your workspace.


octave shipped with ubuntu 11.10 (not sure which buildflags that were used):

octave:1> test_datafile
fullTime =  3.8980
partialTime =  2.9394
Variables in the current scope:

  Attr Name             Size                     Bytes  Class
  ==== ====             ====                     =====  ===== 
       filename         1x11                        11  char
       fullTime         1x1                          8  double
       p                1x1                 3840016000  struct
       p500             1x1                    3840016  struct
       partialTime      1x1                          8  double

Total is 15 elements using 3843856043 bytes

octave:2> 
octave:2> version
ans = 3.2.4
octave:3>



Local modified copy of octave (-O2 -g etc):
octave:1> cd /home/linde
octave:2> 
octave:2> test_datafile
fullTime =  4.2305
partialTime =  0.040248
Variables in the current scope:

   Attr Name             Size                     Bytes  Class
   ==== ====             ====                     =====  ===== 
        filename         1x11                        11  char
        fullTime         1x1                          8  double
        p                1x1                 3840016000  struct
        p500             1x1                    3840016  struct
        partialTime      1x1                          8  double

Total is 15 elements using 3843856043 bytes

octave:3> version
ans = 3.5.0+



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