[Insight-developers] [vtkusers] wx/vtk weirdness

[Bill Lorensen]

I just verified several itk reader problems. I modified the itkIOTests
test driver so that it set the locale to fr_FR (in honor of Mathieu).
Sure enough several tests fail.

I am going to start a discussion to the itk developers' mail list.

Bill

On Fri, Nov 27, 2009 at 11:53 AM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
> I see that itk has similar issues, but only for 2 of its readers. So
> what is the proper way to read floats? With streams?
>
> Bill
>
> On Fri, Nov 27, 2009 at 11:50 AM, Mathieu Malaterre
> <mathieu.malaterre at gmail.com> wrote:
>> Yes.
>>
>> On Fri, Nov 27, 2009 at 5:49 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
>>> Mathieu,
>>>
>>> There are many vtk readers that use sscanf to read floating point
>>> numbers. Does that mean that these readers may also misinterpret
>>> floating point if LC_NUMERIC is different.
>>>
>>> Bill
>>>
>>> On Fri, Nov 27, 2009 at 11:25 AM, Mathieu Malaterre
>>> <mathieu.malaterre at gmail.com> wrote:
>>>> On Fri, Nov 27, 2009 at 5:17 PM, "Eduardo M. Suárez Santana"
>>>> <esuarez at itccanarias.org> wrote:
>>>>> Mathieu Malaterre wrote:
>>>>>> On Fri, Nov 27, 2009 at 4:47 PM, "Eduardo M. Suárez Santana"
>>>>>> <esuarez at itccanarias.org> wrote:
>>>>>>
>>>>>>> This looks weird to me. Spacing of vtkDICOMImageReader depends on
>>>>>>> whether I use wx or not.
>>>>>>>
>>>>>>> Can anyone reproduce?
>>>>>>>
>>>>>>> It fails in vtk-5.2.1 and vtk-5.4.2 on linux, python-2.6.2 and wxpython-2.8.10.1
>>>>>>>
>>>>>>
>>>>>> DICOMParser is using internally sscanf to decode the spacing. It will
>>>>>> fails to work when LC_NUMERIC is not compatible with "C" style. I
>>>>>> believe by default GTK (underlying implementation of wx on linux) sets
>>>>>> the LC_NUMERIC corresponding to your locales.
>>>>>>
>>>>>> HTH
>>>>>>
>>>>> Rethinking.
>>>>>
>>>>> Is not a bug if the correct behaviour depends on setting an unrelated
>>>>> variable (DICOM - LC_NUMERIC)?
>>>>>
>>>>
>>>> I /personally/ believe it is. This is up to the DICOM implementor to
>>>> make sure the reading/writing of floating point value works as per
>>>> DICOM specs (ie. use '.' and not ',').
>>>> Maybe log a bug for that.
>>>>
>>>> 2cts
>>>> --
>>>> Mathieu
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>>>
>>
>>
>>
>> --
>> Mathieu
>>
>