Three measurements, each answering a different question: what one call
costs, how the cost grows with size, and what the other cores save. The
method states the three rules the tools follow, no warm-up, best of several
runs, and cost per unit rather than an absolute figure, so a reader can
reproduce and judge.
The findings are that the numerical kernels are linear and parallelise
well, a day over two thousand satellites costs 0.7 seconds on one core and
81 milliseconds on sixteen, and that interpolation is about ten times
cheaper than propagation. Two combined operations are limited by their
algorithm: greedy planning is quadratically serial, and the duplicate
check on edge insertion squares that quadratic, so threading helps neither.
Eight threads is recommended, since efficiency falls to about half at
sixteen.
The bilingual documentation convention needs a rule for terms, otherwise the
same word gets translated two ways in two files. The glossary separates the
terms that keep their English form, being proper names, abbreviations and
methods that exist only in English in the source literature, from the terms
that have a standard Chinese name and use it directly. It also fixes how a
formula is written, since a formula in a comment has to agree with the code
it describes.
Both languages are written, as the convention requires.
The notes were Chinese only, so a reader arriving from GitHub, which
renders README.md by default, met a wall. Each note now follows the
convention the wider ecosystem uses: English in X.md and Simplified
Chinese in X.zh.md, with a switch at the top of both, the way
zeromicro/go-zero and alist-org/alist present theirs.
The Chinese text moved to the .zh.md name rather than being rewritten, so
nothing was lost, and the English is a translation of the same content
rather than a summary of it.
Two figures in the notes had gone stale and are corrected while
translating: there are thirteen expect assertions rather than twelve,
because apsis-math/src/parallel.rs added one, and the table listed eight
of them rather than all. The layer note no longer quotes an edge count,
which changed as the code grew and was already out of date.
The choice of which loops to thread follows the cost of one item and the
size of the batch, and the note records both ends: the propagation that
gains five fold over a month and barely gains over a day, and the
visibility sweep that is slower in parallel below a few hundred satellites
because a single test costs a few nanoseconds. The interfaces say the same
thing, so a caller knows when to reach for them.
README stated that a crate may only depend on layers to its left, but
nothing checked it, and the wording was self contradicting: the example
given for a cross layer jump was a reverse dependency. Clarify the rule,
add scripts/check-layers.sh to enforce it, run it in CI, and record the
boundary cases in docs/design/layers.md.
apsis-core described Error and Result as the workspace's single error
surface, but no crate uses them: every layer with a domain specific failure
defines its own Error and ErrorKind, whose variants name the concrete
conditions a caller matches on. Correct the doc comment and record the
strategy, including the Option versus Result split and the tolerance
conventions.
ApsisRS contributors