\section{Research number columns and semantic units}
\subsection{Optional siunitx formatting}
\begin{sloppypar}
Formatter=builtin preserves existing output. Load siunitx v3 explicitly and
select \key{formatter=siunitx}; tables and columns also have formatter defaults and
overrides, independent of standalone setup. Drawing keys in column options can
override them. The adapter maps precision and fixed/grouped/scientific display
using public num and unit interfaces, without passing a graphic to an S column.
Missing v3 dependencies produce an error. This is a defined subset of siunitx,
not support for every formatting option or uncertainty input.
\end{sloppypar}
\begin{source}
\usepackage{siunitx}
\usepackage{gradbars}
\gradbar[formatter=siunitx,precision=3,
  unit code={\milli\second},unit text={milliseconds}]{1.23456e1}
\end{source}
Legacy unit remains a literal suffix. Unit code requires the SI formatter and
readable unit text; do not combine both unit forms or attach semantic units to
computed-percent labels. Missing has no suffix and count summaries suppress
units. Automatic descriptions retain raw values and readable unit text rather
than unit macros; explicit alt still replaces the complete description.
\subsection{Decimal points, signs and exponents}
Number \key{align=decimal} applies only to number columns. A table default leaves
text/graphic columns unchanged; explicitly selecting it for a graphic errors.
Both sides are measured across displayed data and group/overall summaries before
width allocation. Align locates the whole number block. Scientific displays
align mantissas and reserve exponent/unit space; \key{precision=0} aligns integer
endpoints and missing labels are centered. Display rounding ties go away from
zero while statistics retain raw values. Increase explicitly insufficient
column widths. Long tables retain the same anchors across pages.
\begin{demo}{Complete example: precision and elapsed time}
\gradbarsloadcsv{precision}{docs/data/precision-time.csv}
\begin{center}
\begin{gradtable}[align=c,header align=c,data=precision,width=\linewidth,style=research,theme=teal,
  formatter=siunitx,group by=family,rank scope=group,group summary=true,
  sort keys={score/descending,time/ascending}]
  \gradcolumn[source=Method]{name}{Method}
  \gradcolumn[source=Family]{family}{Family}
  \gradcolumn[type=bar,source=Score,aggregate=mean,mark=both,
    options={precision=2}]{score}{Score}
  \gradcolumn[type=number,source=Time,aggregate=min,mark=both,
    options={precision=3,better=lower,
    unit code={\milli\second},unit text={milliseconds}}]{time}{Time}
  \gradsummary{Overall}
\end{gradtable}
\end{center}
\end{demo}
Group minimum times are 8.375 and 12 milliseconds. Both Neural scores of 91.5
are group bests, and the missing row acquires no unit.
\begin{demo}{Complete example: metrics of different magnitudes}
\gradbarsloadcsv{magnitudes}{docs/data/magnitudes.csv}
\begin{center}
\begin{gradtable}[align=c,header align=c,data=magnitudes,style=research,theme=violet,
  width=0pt,text width=20mm,column sep=6pt,
  row stretch=1.15,row padding=1pt]
  \gradcolumn[source=Method]{name}{Method}
  \gradcolumn[type=number,source=Residual,aggregate=mean,mark=both,
    options={precision=2,number format=scientific,better=lower}]{residual}{Residual}
  \gradcolumn[type=number,source=Count,aggregate=sum,formatter=siunitx,
    options={precision=2,number format=scientific}]{count}{Count}
  \gradcolumn[type=number,source=Rate,aggregate=mean,
    options={precision=3,unit={\,s}}]{rate}{Rate}
  \gradsummary{Summary}
\end{gradtable}
\end{center}
\end{demo}
The residual mean is approximately $-7.9167\times10^{-4}$ and the Count sum is
$4.175\times10^6$. Display precision changes neither statistic.

This number-only table uses \key{width=0pt} for natural sizing, avoiding unused width in the method column.