read data subsets from HDF5

[Dr. Lutz Wendorff]

Greetings to all,

It seems I can load easily HDF5 files into a struct, in this example about 
1.8GB of memory. I would like to read just a few single data sets:

New to octave, my major goal right now is to use it as a plot engine. This is 
what I got so far:
octave:1> load dl_one0.h5
octave:2> whos
Variables in the current scope:

  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  ===== 
       ans         1x11                        92  cell
       mag         1x1                 1762381920  struct

Total is 12 elements using 1762382012 bytes

octave:3> fieldnames(mag)
ans =

{
  [1,1] = lines
}


octave:4> isstruct(mag)
ans =  1
octave:5> isstruct(mag.lines)
ans =  1
octave:6> fieldnames(mag.lines)
octave:7> isstruct(mag.lines._10)
ans =  1
octave:8> isstruct(mag.lines._10.SECOND)
ans =  1
octave:9> fieldnames(mag.lines._10.SECOND)
ans =

{
  [1,1] = _0
  [2,1] = C
}

octave:10> fieldnames(mag.lines._10.SECOND)
ans =

{
  [1,1] = _0
  [2,1] = C
}

octave:11> isstruct(mag.lines._10.SECOND.C)
ans = 0
octave:12> mag.lines._10.SECOND.C(1,1)
ans =  62327
octave:13> mag.lines._10.SECOND.C(1,2)
ans =  6.2327e+04
octave:14> mag.lines._10.SECOND.C(1,200)
ans =  6.2347e+04

octave:15> clear("mag")

Sorry for this long list: There are many mag lines which contain data channels 
consisting of columns (double), SECOND for time. (1-column-data sets)

How can I read _selected_ channels like SECOND of line "10" into an array in 
octave? Not the whole structure?

Many thanks, Lutz.


-- 
Dr. Lutz Wendorff
2550 Church Street
North Gower / Ottawa
Ontario K0A 2T0, CANADA
Tel 613-489-3438
address@hidden