Comments on The NAG Blog: Calling routines from the NAG Fortran and C librar...

Following this description of how to call NAG rout...

2011-12-09T16:44:52.647Z

Following this description of how to call NAG routines from LabVIEW, I've written some examples illustrating some aspects of this work. They're now available for download from our LabVIEW page which contains a link to an archive containing eighteen LabVIEW examples that use a variety of NAG routines and methods.

Many thanks for the helpful comment, Conway, and f...

2011-10-24T10:52:59.804+01:00

Many thanks for the helpful comment, Conway, and for the pointer to your article which contains a wealth of further useful information on this topic. Your main point here about the difference between calling the Fortran and C libraries from LabVIEW is, I think, well-taken: as noted, I used an integer for the address of the C structure. This satisfies the requirements of the calling protocol, but it's not possible (or at least, much more difficult) to make any use of the contents of the structure - i.e. we can't check for any error conditions.

This is an excellent introduction to calling NAG F...

2011-10-19T00:29:27.156+01:00

This is an excellent introduction to calling NAG Fortran and C routines from LabVIEW.

For me the key difference between the two libraries is how they handle fail conditions. The fortran routines pass a single integer value which determines how an error will be handled (hard or soft fail), and receives the error code on completion of the routine. Control of error handling with the C library functions requires the passing of C structures which is not at all straightforward from LabVIEW.

In principle, calling C routines from LabVIEW appears to be straightforward as LabVIEW follows many of the C conventions. However, as long as the differences between Fortran and C, such as the handling of strings and array are kept in mind both are reasonable easy to handle from LabVIEW. I've written more details on this here.

The above link also contains some hints on making the LabVIEW interface to the NAG libraries more readable, such as displaying terminal names in the call library function node and grouping similar input or output nodes together in clusters.