Re: equivalent for C-style init: structname varname[] = {...} ?

[Sergei Steshenko]

>________________________________
> From: Yury T. <address@hidden>
>To: address@hidden 
>Sent: Monday, November 12, 2012 6:09 PM
>Subject: equivalent for C-style init: structname varname[] = {...} ?
> 
>Hi all
>
>I can't find or figure out an equivalent for the C-style variable
>initialization in Octave:
>
>structname varname[] = { {<field1_value>,<field2_value>},
>{<field1__value>,<field2_value>} };
>
>This example of what I'd like to do in Octave is assuming structname having
>two fields and the size of the array in structname units is defined by the
>number of constant initializers.
>
>Or are there good replacements for this sort of constructs, perhaps? 
>
>Please advise.
>
>
>
>--
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>

Have a look at the code below I once published to this list - maybe it's 
close(r) to what you need.

Regards,
  Sergei.



"
octave:1> system("cat -n /home/sergei/junk/consistent_struct.m");
     1  # copyright Sergei steshenko, 2012.
     2  # released under 3 clause BSD license.
     3  # tested under octave-3.6.2.
 
    4  # Matlab (tm) users are explicitly encouraged to to trivially 
modify the code ('#' -> '%') if they like it and wnat to use it.
     5  # the function is supposed to implement functionality similar to 
associative arrays in Perl/Python/C++
     6
     7  function os = consistent_struct(varargin)
     8    if(rem(length(varargin),2))
     9      error("there must be even number of input arguments");
    10    endif
    11
    12    os = [];
    13    for struct_field_number = 1:2:length(varargin)
    14      #fprintf(stderr, "key: %s\n", varargin{struct_field_number});
    15      key = varargin{struct_field_number}; # no check of 'key' 
correctness is performed
    16      val = varargin{struct_field_number + 1};
    17      os = setfield(os, key, val);
    18    endfor
    19  endfunction
    20
    21
    22  # comment out the following test cases if you want yo just use the 
function
    23  os = consistent_struct("one", [1 2 3], "two", [5 6 7 8; 9 10 11 12], 
"three", 33, "four", {"foo", 44, "bar"});
    24
    25  # Przemek Klosowski's test case:
    26  samples = consistent_struct\
    27              (
    28              "patient", {"Bob", "Kevin", "Bob" , "Andrew"},
    29              "age",     [ 45  ,  52    ,  45   ,  23     ],
    30              "protein", {"H2B", "CDK2" , "CDK2", "Tip60" },
    31              "tube"   , [ 3   ,  5     ,  2    ,  18     ]
    32              );
octave:2> source("/home/sergei/junk/consistent_struct.m");
octave:3> size(samples.age)
ans =

   1   4

octave:4> samples.age(2)
ans =  52
octave:5> samples
samples =

  scalar structure containing the fields:

    patient = 
    {
      [1,1] = Bob
      [1,2] = Kevin
      [1,3] = Bob
      [1,4] = Andrew
    }
    age =

       45   52   45   23

    protein = 
    {
      [1,1] = H2B
      [1,2] = CDK2
      [1,3] = CDK2
      [1,4] = Tip60
    }
    tube =

        3    5    2   18


octave:6> samples.patient{2}
ans = Kevin
octave:7> 
".

It is not at all clear from Octave's 'help setfield' that "setfield(os, key, 
val);" is a valid construct.

Matlab documentation ( http://www.mathworks.com/help/techdoc/ref/setfield.html 
) OTOH in very beginning says:

"setfield function creates the field and assigns the specified value. Pass 
field references as strings.".