the routine gifti_value_gifti_image, as used in gifti_tool and my own reader, returns this when reading one of the caret files:

** invalid nvpair value[9], name = 'pubmed_id'
++ gifti_image 'Human.colin.Cerebral.R.VERY_INFLATED.71723.surf.gii' is INVALID

so is this a valid file? or should i not exit my reader if gifti_valid_gifti_image fails? i'd prefer to exit with error and not ignore the messages.

Hi Nick,

I'll make that message more clear. The 'value' is invalid, which means it is NULL in that case.

The name is there, but not the value. I believe that makes it an invalid file.

- rick

The value field of a metadata element allows the user to enter any value he or she desires. I interpret this to mean no value, or an empty string, is acceptable.

Hi John,

That make sense, though it begs the question of what about a 'value' without a 'name'. Are you allowing that?

It would also makes sense to me that if there is no actual metadata, there is nothing to store in the dataset.

Do others have thoughts on this? Is any case considered invalid?

- rick

Rick,

You are correct. Having a MetaData value without a name would not make sense. We should be able to require the Name child of MetaData contain text for a metadata element when we transition from a DTD to an XML schema (XSD).

I believe we defined metadata as being optional. In the DTD, MetaData is listed as an optional child of both the GIFTI and DataArray elements. While it is a very good idea to include metadata in a GIFTI file, I think we should continue to allow it to be optional.

John Harwell

John,

I think my comment about requiring metadata was not clear.

My meaning was that the actual data part of metadata is the 'value'. So for a MetaData element to have a Name but no Value is to say that there is no actual metadata in that MetaData element.

So my question was simply about that MetaData element, is it worth storing it in the dataset? I did not mean to suggest there was no point in having a dataset without MetaData.

I do not have a strong opinion about this, but want to be clear that it makes just as much sense to me not to allow such a MetaData element.

- rick

Hi Nick, Hi John,

Since no one else has offered an opinion, I have changed the library to consider a MetaData element without its Value to be valid. That is included in the gifticlib-0.0.14 package which is now available.

Thanks,

- rick