[pymvpa] Question about NiftiDataset

[Michael Hanke]

Hi,

On Mon, Apr 06, 2009 at 03:12:38PM +0200, Valentin Haenel wrote:
> Hi,
> 
> when i look at the documentation for NiftiDataset, i see that samples has a
> default of None. This seems to suggest i could use:
> 
> NiftiDataset()
> 
> to instantiate an empty dataset, which however raises a ValueError
> 
> My use case is such that i want to instantiate an empty dataset and then use
> "+=" to successively populate the dataset in a loop.

I see no easy solution to this problem. The presence or absence of the
samples argument is the trigger for the 'copy-constructor-behavior' of the
dataset classes -- a feature that is heavily used in PyMVPA. Since
Python cannot handle more than one contructor it has been implemented
this way.

It might be worth to evaluate that carefully and see whether such change is
doable. We might achieve that during the upcoming refactoring of the
dataset base class -- will keep it in mind...


Thanks,

Michael


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