Use another routine if sub-arcsec accuracy is critical. The galactic coordinate routine is rigorously accurate, and precesses to 1950 before transforming. The ecliptic coord. The program rejects input outside 1900-2100. When porting to a new machine, run tests to ensure correctness and accuracy.
Experience shows that compiler peculiarities arise surprisingly often.
When porting to another machine or compiler, test that the accuracy is sufficient. The user of this program is responsible for interpreting results correctly. I disavow any legal liability for damages caused by use of this program. Commercial users must license. Please communicate problems or suggestions to the author, John Thorstensen, Dept.