Formatting¶

Summarizes SPEC.md §6; SPEC.md is authoritative.

Formatting happens at build time from the raw recorded value, so changing a format never requires a re-run. A value has a default fmt (set at record time); a citation can override it with \vouch[fmt]{key}.

Grammar¶

Format strings must be safe inside LaTeX source and inside \csname, so the grammar is ASCII-only and uses letters for symbols that are unsafe in LaTeX (% starts a comment, non-ASCII is unsafe in control-sequence names, babel makes :;!? active in some languages):

fmt     := [sign] [","] ["." precision] [type] {suffix}
sign    := "+"                               always show the sign
","                                          thousands grouping, rendered {,}
type    := "f" | "e" | "g" | "d" | "pct" | "s"
suffix  := "x"      append \times           (multipliers: 1.62\times)
         | "u"      append the unit          (12.3\,ms)
         | "ci"     Stat as mean [lo, hi]    (95% CI)
         | "to"     tuple as a \to b         (56 \to 32)

On the Python side, fmt=".1%" is accepted as an alias for .1pct, and so is "{:.1%}". Aliases are normalized when recorded; LaTeX sources must use the canonical form. Named formats from [format] named can be used anywhere a format can: \vouch[pct1]{key}.

Rendering table¶

Raw value	fmt	Rendered LaTeX
`0.93214`	`.1pct`	`93.2\%`
`0.93214`	`.2f`	`0.93`
`18535`	`,d`	`18{,}535`
`1.87e-14`	`.1e`	`\ensuremath{1.9\times10^{-14}}`
`1.6247`	`.2fx`	`\ensuremath{1.62\times}`
`-0.9212`	`.2f`	`\ensuremath{-0.92}` (true minus sign)
`0.0213`	`+.1pct`	`\ensuremath{+2.1}\%`
`Stat(0.93214, 0.0041, 5)`	`.1pct`	`\ensuremath{93.2 \pm 0.4}\%`
`Stat(0.93214, 0.0041, 5)`	`.1pctci`	`93.2\% [92.7, 93.7]`
`(41.2, 53.4)`	`.0f`	`41--53`
`(56, 32)`	`dto`	`\ensuremath{56 \to 32}`
`12.34` + `unit="ms"`	`.1fu`	`12.3\,ms` (siunitx mode: `\qty{12.3}{\ms}`)
`"ResNet-50"`	`s`	`ResNet-50` (LaTeX-escaped)

Rules¶

Rounding is half-up by default (0.125 → 0.13), the way readers expect, not the banker's rounding of format(). half_even is available.
Math. Output containing \times, \pm, \to, ^, or a leading minus sign is wrapped in \ensuremath{}, so \vouch works in text and in math.
Default float format. If no format is given, .3g is used, and the build prints an info note that a float was cited without an explicit format.
siunitx mode emits \num{…} / \qty{…}{…} instead of hand-built numbers, for papers that already use siunitx.
Pre-rendering. Every (key, fmt) pair the paper actually uses is found by scanning and rendered in advance. LaTeX never computes anything.