Following on from modified total deviation mtotdev() the Hadamard total deviation htotdev() algorithm is very similar but instead of phase data takes frequency data. Now included in allantools.

Here's a comarison against Stable32 and the NIST SP 1065 table values.

There's no bias-correction for now, and apparently it is customary not to use htotdev(m=1) at an averaging-factor of 1, but instead use ohdev(m=1). This is why the 'raw' value from allantools at tau=1 in the plot below is a factor of 2 too low.

htotdev_2016-03-27Both mtotdev() and htotdev() are very slow algorithms - help with making them faster would be appreciated!