[NTG-context] Placing number in \sqrt

[Hans Hagen]

On 5/4/2020 8:47 AM, context at vivaldi.net wrote:
> Hello,
> 
> compare placing "3" in the following examples:
> 
> ----
> \starttext
>    $\sqrt[3]{5}$ % (1)
>    \par
>    $\sqrt[3~]{5}$ % (2)
> \stoptext
> ----
> 
> In the first case, the "3" is placed naturally by ConTeXt and placed 
> more in the centre of "V" part of the square sign.
> 
> In the second example, the "3" is shifted manually by adding "~" and the 
> final placement seems to me a bit better.
> 
> What is your opinion - is the case (1) OK/intended and user should avoid 
> any manual shifting?
> 
> Or manual shifting is OK? Or is there a way to affect this placement 
> globally in ConTeXt, e.g. setting an internal variable?

The placement is driven by the font so kind of part of the design. There 
is a whole bunch of parameters that drives placement and there is one 
that deals with the spacing after the degree. Here are some examples.

\starttext

     \def\R {\Umathradicaldegreeafter\textstyle0pt}
     \def\RR{\Umathradicaldegreeafter\textstyle\dimexpr
        \Umathradicaldegreeafter\textstyle+.1em\relax}
     \def\RRR{\frozen\Umathradicaldegreeafter\textstyle\dimexpr
        \Umathradicaldegreeafter\textstyle+.2em\relax}

     $    \sqrt[3]{5}   \RR\sqrt[3]{5}  \sqrt[3]{5} $\par
     $    \sqrt[3]{5} {\RRR\sqrt[3]{5}} \sqrt[3]{5} $\par
     $ \RR\sqrt[3]{5} {\RRR\sqrt[3]{5}} \sqrt[3]{5} $\par

     {\R  $\sqrt[3]{5} \sqrt[3]{5} \sqrt[3]{5} $\par
     {\RR $\sqrt[3]{5} \sqrt[3]{5} \sqrt[3]{5} $\par
     {\RRR$\sqrt[3]{5} \sqrt[3]{5} \sqrt[3]{5} $\par

\stoptext

Changing these parameters inside math is kind of pseudo global: the 
value at the end of the first pass is used for the whole formula. 
However, in lmtx you can cheat by using the \frozen prefix to make it 
behave local.

If we can come up with a proper name for a parameter we can make it a 
setting. One of these things that Aditya and I will to discuss when we 
have time and are in math mood. (There is much more in math we could 
control if needed, but often in the end that control is not that much 
needed at all.)

Hans

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