Error with function handles of object methods

[John W. Eaton]

On 24-Jun-2009, WMennerich wrote:

| Hello,
| I found a bug using objects:
| In short words: Function handles of object functions (methods) within
| the class directory (beginning with '@') can not be created.
| 
| I use Octave V3.2.0 (mingw binary) on WindowsXP.
| 
| I hope, this bug report contains enough details,
| otherwise just ask please.
| 
| 
| W.Mennerich
| 
| 
| 
| In the following the tests I made:
| 
| 
| 
| 
| 
| function test (<scalar>,<scalar>)
| [constructor in the '@test' directory
| *********************************
| function newtest=test(att1, att2)
| %constructor
| 
| switch nargin
| case 0
| newtest.att1=[];
| newtest.att2=[];
| case 2
| newtest.att1=att1;
| newtest.att2=att1+att2;
| end
| 
| newtest=class(newtest,'test');
| **********************************
| 
| 
| function sumAtts(<test>)
| [a method in the '@test' directory
| **********************************
| function res=sumAtts(this)
| res=this.att1+this.att2;
| 
| 
| 
| function get(<test>,<string>)
| [for testing function overloading,
| also inside '@test']
| **********************************
| function att=get(this,nameAtt)
| att=this.(nameAtt);
| 
| 
| 
| Test environment:
| ##################################
| ##################################
| 
| * Create all files
| 
| * Create '@test'
| 
| * Put all files into '@test'
| 
| * Put '@test' into octave path
| 
| 
| 
| Running the tests:
| ##################################
| ##################################
| 
| %Testing the class:
| %create three objects and put them into a cell array:
| 
| mytest1=test(33,44)
| mytest2=test(66,88)
| mytest3=test(132,176)
| 
| allmytests={mytest1 mytest2 mytest3}
| 
| 
| %Workspace of octave shows:
| 
| 
|   Attr Name            Size                     Bytes  Class
|   ==== ====            ====                     =====  =====
|        allmytests      1x3                         48  cell
|        mytest1         1x1                         16  test
|        mytest2         1x1                         16  test
|        mytest3         1x1                         16  test
| 
| 
| 
| 
| 
| %Testing of the sumAtts(<test>) function:
| 
| > sumAtts(mytest1)
| ans =  110
| 
| 
| > sumAtts(mytest2)
| ans =  220
| 
| 
| > sumAtts(mytest3)
| ans =  440
| 
| 
| 
| 
| 
| 
| %Function 'sumAtts' as input of an anonymous function works:
| 
| > cellfun(@(x) sumAtts(x),allmytests)
| ans =
| 
|    110   220   440
| 
| 
| 
| %Also the (overloaded) function  'get' works fine:
| > cellfun(@(x) get(x,'att1'),allmytests)
| ans =
| 
|     33    66   132
| 
| 
| %Using cellfun with a sumAtts handle does not work:
| 
| > cellfun(@sumAtts,allmytests)
| error: error creating function handle "@sumAtts"
| error: evaluating argument list element number 1
| error: error creating function handle "@sumAtts"
| error: evaluating argument list element number 1
| 
| 
| %The same also with overloaded 'get' function, gives another error:
| 
| > inStrings={'att1' 'att1' 'att1'}
| inStrings =
| 
| {
|   [1,1] = att1
|   [1,2] = att1
|   [1,3] = att1
| }
| 
| > cellfun(@get,allmytests,inStrings)
| error: octave_base_value::array_value(): wrong type argument `class'
| error: get: expecting graphics handle as first argument

Jaroslav's recent changes seem to fix this problem, but

  cellfun(@sumAtts,allmytests)

still doesn't work for me.

| %Try to create a function handle outside of cellfun:
| 
| > fun=@sumAtts
| error: error creating function handle "@sumAtts"

Jaroslav, is this supposed to work now?

jwe