APT and APTB are algorithms designed to time isolated and binary pulsars, respectively, given an input .par and .tim file. The algorithm uses covariances between fit parameters to project possible models forward in time. By combining these predictive models with the statistical F-Test, along with several features such as phase wrapping, checking for bad data, and choosing appropriate starting TOAs, the algorithms encode the decisions a scientist makes when fitting a pulsar into an easy-to-run script with an average runtime of several minutes for APTB and tens of minutes to hours for APTB. APT was tested on 100 simulated systems, created using the included simdata.py script, and solved 97% of the systems. APT fits for the four main paramaters, F0 (spin), RAJ (Right Ascension), DECJ (Declination), and F1 (spindown). APTB was first in phase connecting PSRs J1748−2446aq and J1748−2446at, and fits for the four main parameters as well as binary parameters.
APT is described in the paper Algorithmic Pulsar Timing, available on the ArXiv at https://arxiv.org/abs/2012.07809. APTB is described in the paper Algorithmic Pulsar Timer for Binaries, available on the ArXiv at https://arxiv.org/pdf/2310.10800. APT and APTB are dependent on the pulsar timing package PINT, available at (https://github.com/nanograv/PINT) and described in the paper PINT: A Modern Software Package for Pulsar Timing, available at https://arxiv.org/abs/2012.00074