Hi Fabrice,

You can use a construction such as:

\starttext
\ctxlua{x = math.floor(10^3*math.pi)/10^3; context(x)}
\stoptext

Best regards: OK

On 19 Apr 2017, at 15:25, Fabrice Couvreur <fabrice1.couvreur@gmail.com> wrote:

Hello,
I do not know Lua but I'll learn later. How to display only 3 digits after the decimal point ?
thank you,
Fabrice

\starttext
\startlinecorrection[blank]
      \startmidaligned
        \bTABLE[width=2cm,offset=0.8ex,align={lohi,middle}]
        \bTR
        \bTD \math{P} \eTD
        \bTD \math{m} \eTD
        \bTD \math{g_M} \eTD
        \eTR
        \bTR
        \bTD \math{1.6} \eTD
        \bTD \math{0.4} \eTD
        \bTD \startluacode context(1.6/0.4)\stopluacode \eTD
        \eTR
        \bTR
        \bTD \math{3.1} \eTD
        \bTD \math{0.8} \eTD
        \bTD \startluacode context(3.1/0.8)\stopluacode \eTD
        \eTR
        \bTR
        \bTD \math{4.3} \eTD
        \bTD \math{1.2} \eTD
        \bTD \startluacode
                context(4.3/1.2)
              \stopluacode
        \eTD
        \eTR
        \bTR
        \bTD \math{5.8} \eTD
        \bTD \math{1.6} \eTD
        \bTD \startluacode context(5.8/1.6)\stopluacode \eTD
        \eTR
        \bTR
        \bTD \math{7.5} \eTD
        \bTD \math{2} \eTD
        \bTD \startluacode context(7.5/2)\stopluacode \eTD
        \eTR
        \eTABLE
      \stopmidaligned
    \stoplinecorrection
\stoptext
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