GPKit 1.3.0

GPKit 1.3.0 adds one thing, and nothing that worked in 1.2 breaks.

Propagator can now start from the epoch the way David Vallado's C++ reader works it out from a TLE: Propagator(set, epochReading: .vallado). That's how his published tcppver.out was made, so in that mode GPKit matches it to its last digits. All 33 of his test sets get exactly his reader's epoch, and set 23333, the very eccentric one, comes within 4.9e-9 km of his output. The default stays the exact epoch (.exact), which is up to about 20 microseconds off his. Propagator(set) works just as before.

The gpkit-gpconf adapter now declares the constants its propagation uses. It takes --epoch vallado for a second gpconf run beside the default one. GPKit's recorded result still uses the exact epoch.

The playground's module built from this tag is attached below, with its SHA-256 and the output of its checks, along with the gpkit command-line downloads for Linux, macOS and Windows. The macOS one still isn't signed, so the first time macOS will block it: run xattr -d com.apple.quarantine gpkit where you unpacked it, or open it once and choose Open Anyway in System Settings, Privacy & Security.

The full list is in the changelog.