D.3 Changes for CDF V2.5

Several changes have been made to the CDF distribution for V2.5. CDF V2.5 differs from CDF V2.4 in the following ways.

1. The distribution has been ported to the Macintosh (MacOS 7.0). A version of the CDF library is available for Symantec THINK C and Macintosh Programmer's Workshop (MPW) C and Fortran applications. The CDF toolkit programs have user interfaces typical of Macintosh applications.
2. A shareable version of the CDF library is available on DEC Alphas running OSF/1. Because of this, support for CDF's IDL interface has also been added for that platform.
3. Create/write access for a CDF with any supported encoding is now supported on all platforms. Previous CDF distributions only supported host and network encodings when creating/writing a CDF.
4. Support for Version 1 CDFs has been eliminated. If necessary, use CDF V2.4 to convert your Version 1 CDFs to Version 2 CDFs before accessing them with CDF V2.5.
5. A cache size qualifier has been added to most of the CDF toolkit programs. With this qualifier, the cache size to be used with open CDFs can be adjusted for increased performance.
6. Most of the functionality of CDFinquire has been moved to SkeletonTable. CDFinquire may still be used to inquire the version of the CDF distribution being used and the default qualifiers for the CDF toolkit programs. This was done in an effort to eliminate redundant capabilities between the two programs.
7. The ability to delete variables, attributes, and attribute entries from a CDF has been added.
8. An operation has been added to the Internal Interface which allows variable records to be allocated in a single-file CDF (but not yet written). The application program is then expected to write to the allocated variable records before closing the CDF. This method is more efficient than using ``initial records''.
9. The option of converting -0.0 to 0.0 by the CDF library when reading from a CDF now also applies to writing to a CDF. When -0.0 to 0.0 mode is enabled, -0.0 would be converted to 0.0 by the CDF library before being written to a CDF.
10. An encoding qualifier has been added to the CDFconvert toolkit program to allow any supported encoding to be selected for the destination CDF of a conversion.
11. Support for the Obsolete Interface has been eliminated. Applications written for CDF Version 1 must now be modified for the Standard (or Internal) Interface of CDF Version 2.
12. The CDF V2.5 distribution is configured for a default format of single-file (previous CDF distributions defaulted to multi-file). This may be changed before building/installing the CDF distribution if desired.
13. A statistics qualifier has been added to some of the CDF toolkit programs. When selected, caching statistics are displayed when a CDF is closed.
14. CDFskeleton has been renamed to SkeletonCDF. This should ease the confusion experienced by some users. SkeletonTable creates a skeleton table and SkeletonCDF creates a skeleton CDF. (Note that the symbol CDFSKELETON on VMS systems and the environment variable cdfskeleton on UNIX systems is still defined in the corresponding ``definitions'' file for compatibility with existing user systems.)
15. CDFs created with CDF V2.5 will use less disk space than CDFs created with previous CDF distributions. The savings will consist of 1689 bytes per CDF regardless of its contents plus an additional savings of 128 bytes per variable. NOTE: A side effect of this is that V2.5 CDFs may only be read with the CDF V2.5 distribution. Previous CDF distributions will not be able to read CDFs created with CDF V2.5.
16. The CDF library has been modified to use less memory for each open CDF (unless a large cache size is specified). This should ease the memory limitation problems encountered on the IBM PC and Macintosh. Access to attribute entry data may be slower because of this change.
17. Assumed attribute scopes are no longer supported. The CDF library will now automatically convert an assumed scope to its definite equivalent scope. Because of this the CDFscope toolkit program has also been eliminated. If necessary, use CDF V2.4 to correct attribute scopes. Note that the Internal Interface of CDF V2.5 may also be used to correct an attribute scope.
18. Dynamic-link libraries (DLLs) are now supplied with the MS-DOS distribution for Microsoft and Borland Windows applications.
19. Qualifiers have been added to CDFedit which allow attribute entries to either be displayed with the attributes or on separate menus (with one for each attribute).