[Octave-bug-tracker] [bug #47763] Loading a function handle variable from a MAT-file

[Guillaume]

URL:
  <http://savannah.gnu.org/bugs/?47763>

                 Summary: Loading a function handle variable from a MAT-file
                 Project: GNU Octave
            Submitted by: gyom
            Submitted on: Fri 22 Apr 2016 05:11:51 PM GMT
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: None
                  Status: None
             Assigned to: None
         Originator Name: Guillaume
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: dev
        Operating System: GNU/Linux

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Details:

When loading a MAT-file containing a function handle, it doesn't work if the
path to the function has changed (but is still in the function search path).
See the following piece of code:


>> % have foo.m in /tmp 
>> type /tmp/foo.m
>> addpath /tmp
>> % create foo.mat with Matlab
>> cd ~
>> address@hidden;
>> functions(f)
>> save foo.mat f -v6
>>
>> % load when file is where expected and in the path
>> addpath /tmp
>> load foo.mat
>> functions(f)
>> f()
>>
>> % load when file is where expected but not in the path
>> rmpath /tmp
>> load foo.mat
>> functions(f)
>> f()
>>
>> % load when file is elsewhere in the path
>> movefile('/tmp/foo.m',pwd)
>> load foo.mat
>> functions(f)
>> f()


Octave does:


>> % load when file is where expected and in the path
>> addpath /tmp
>> load foo.mat
>> functions(f)
ans =

  scalar structure containing the fields:

    function = foo
    type = simple
    file = /tmp/foo.m

>> f()
Hello
>> % load when file is where expected but not in the path
>> rmpath /tmp
>> load foo.mat
>> functions(f)
ans =

  scalar structure containing the fields:

    function = foo
    type = simple
    file = /tmp/foo.m

>> f()
Hello
>> % load when file is elsewhere in the path
>> movefile('/tmp/foo.m',pwd)
ans = 1
>> load foo.mat
error: no such file, '/tmp/foo.m'
>> functions(f)
ans =

  scalar structure containing the fields:

    function = foo
    type = simple
    file = /tmp/foo.m

>> f()
error: foo: no longer valid function handle


while Matlab does:


>> % load when file is where expected and in the path
>> addpath /tmp
>> load foo.mat
>> functions(f)

ans = 

    function: 'foo'
        type: 'simple'
        file: '/tmp/foo.m'

>> f()
Hello
>> % load when file is where expected but not in the path
>> rmpath /tmp
>> load foo.mat
>> functions(f)

ans = 

    function: 'foo'
        type: 'simple'
        file: ''

>> f()
Undefined function or variable 'foo'.
 
>> % load when file is elsewhere in the path
>> movefile('/tmp/foo.m',pwd)
>> load foo.mat
>> functions(f)

ans = 

    function: 'foo'
        type: 'simple'
        file: '/home/foo/foo.m'

>> f()
Hello


So Octave finds the function when it's not in the search path but in its
initial location (Matlab doesn't, appropriately) and doesn't find the function
if it's in the search path but not in its initial location.

I attach the foo.mat file created with Matlab to this bug report.



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File Attachments:


-------------------------------------------------------
Date: Fri 22 Apr 2016 05:11:51 PM GMT  Name: foo.mat  Size: 832B   By: gyom

<http://savannah.gnu.org/bugs/download.php?file_id=36980>

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