Following up on the work-around, here is my improved code for xtable.
What doesn’t work is:
* alignment on the decimal separator takes place only in the first column with
decimals (i.e. B), not on the following one; this is independent of R1 having
a decimal value in this column or not
* row

Hi Wolfgang,
you are (of course) right again. I realised that I wouldn’t get the expected
behaviour after checking the snippet isolated from my document’s context, where
it is embedded in a \startplacetable[…]{}{}. I’m still learning to get the gist
of the \doifs, the curly and square

Benjamin Buchmuller schrieb am 07.05.2020 um 19:41:
Hi Wolfang,
Thank you for your reply. I have indeed not explained my intended result very
clearly.
1.
Primarily, I need to get the two values aligned at the digit separator of the
first and second number respectively and overall at the ±

Hi Wolfang,
Thank you for your reply. I have indeed not explained my intended result very
clearly.
1.
Primarily, I need to get the two values aligned at the digit separator of the
first and second number respectively and overall at the ± sign. I’m working in
an xtable, where I have entries

Benjamin Buchmuller schrieb am 07.05.2020 um 17:31:
Hi,
I’m trying to get
\digits{15.0=}±\digits{1.00}
\digits{_8.12}±\digits{0.34}
horizontally aligned as
15.0 ±1.00
8.12±0.34
But I get
15.0±1.00
8.12±0.34
instead.
From the source (phys-dim.mkiv), I can see that “=“ should expand

Hi,
I’m trying to get
\digits{15.0=}±\digits{1.00}
\digits{_8.12}±\digits{0.34}
horizontally aligned as
15.0 ±1.00
8.12±0.34
But I get
15.0±1.00
8.12±0.34
instead.
From the source (phys-dim.mkiv), I can see that “=“ should expand to
\hphantom{0}. (I think \zeropoint in the table is