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
>
