Summary of differences in arcseconds

Green means < 10 milli-arcsec, orange < 1 arcsec and red > 1 arcsec

FK5 to Horizontal

Tool 1 Tool 2 Median Mean Max Std. Dev.
astropy casa 0.628569 2.353126 12.666443 3.811184
astropy pyast 4.493746 4.845908 9.765197 2.768175
astropy pyephem 4.713086 5.464836 12.965994 3.484395
astropy skyfield 0.001551 1.299845 8.340911 2.725876
casa pyast 3.400792 3.813633 9.622002 2.441991
casa pyephem 3.320928 3.526254 10.207578 2.829381
casa skyfield 0.628495 1.057411 4.415970 1.119046
pyast pyephem 0.858755 1.107748 3.826224 0.844204
pyast skyfield 3.275504 3.551012 9.768754 2.741279
pyephem skyfield 3.663951 4.168958 10.593121 2.584348