Re: suggestion concerning names of attributes in dimension scale API

Hi

well, I guess I am a candidate

replying to Ed's original request, all these decisions are discussed in our 
weekly HDF5 1 hour meeting. We'll add that request to a discussion item, and 
thank you for your support

Pedro

At 01:01 PM 8/8/2005, you wrote:
>Hi Ed,
>    Sounds like a reasonable idea to me.  With Bob leaving soon, someone here
>(possibly me :-)  needs to take over our dimension scale data model.  Any
>takers?
>
>    Quincey
>
>> I have been using dimension scales to store dimension data. The
>> dimension scale code puts several attributes on the datasets to store
>> dimensional metadata. This fragment from h5dump illustrates:
>> 
>>       DATASET "Distance" {
>>          DATATYPE  H5T_IEEE_F32LE
>>          DATASPACE  SIMPLE { ( 3 ) / ( 3 ) }
>>          DATA {
>>          (0): 0, 0, 0
>>          }
>>          ATTRIBUTE "CLASS" {
>>             DATATYPE  H5T_STRING {
>>                   STRSIZE 16;
>>                   STRPAD H5T_STR_NULLTERM;
>>                   CSET H5T_CSET_ASCII;
>>                   CTYPE H5T_C_S1;
>>                }
>>             DATASPACE  SCALAR
>>             DATA {
>>             (0): "DIMENSION_SCALE"
>>             }
>>          }
>>          ATTRIBUTE "NAME" {
>>             DATATYPE  H5T_STRING {
>>                   STRSIZE 9;
>>                   STRPAD H5T_STR_NULLTERM;
>>                   CSET H5T_CSET_ASCII;
>>                   CTYPE H5T_C_S1;
>>                }
>>             DATASPACE  SCALAR
>>             DATA {
>>             (0): "Distance"
>>             }
>>          }
>>          ATTRIBUTE "REFERENCE_LIST" {
>>             DATATYPE  H5T_COMPOUND {
>>                H5T_REFERENCE "dataset";
>>                H5T_STD_I32LE "dimension";
>>             }
>>             DATASPACE  SIMPLE { ( 2 ) / ( 2 ) }
>>             DATA {
>>             (0): {
>>                   DATASET 4392 /Adam/Able/Billy_goat_gruff ,
>>                   2
>>                },
>>             (1): {
>>                   DATASET 9088 /Adam/Cain/Grumpy_the_camel ,
>>                   2
>>                }
>>             }
>>          }
>>       }
>> 
>> 
>> This shows a dimension scale with attributes named CLASS, NAME, and
>> REFERENCE_LIST.
>> 
>> Might I suggest that the names of the attributes be preceded with an
>> underscore? (For example _NAME instead of NAME.)
>> 
>> The reason is that these attribute names will not be available to
>> users. If the user tries to create an attribute named NAME, he will
>> get an error because one already exists. (This is true in both netCDF
>> and HDF5).
>> 
>> It's certain that some users somewhere have used attributes called
>> "NAME." That's why an underscore would be a good idea.
>> 
>> Thanks!
>> 
>> Ed
>> -- 
>> Ed Hartnett  -- ed@xxxxxxxxxxxxxxxx
>> 

</Pedro Vicente Nunes>
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