\starttext
\startMPcode{doublefun}
draw lmt_function
[
xmin=0, xmax=10,
xstep=.05,
ymin=-2, ymax=2,

code="1.5 * math.cosd(240 * math.sqrt(x))",

xlabels="no",ylabels="no",

sx=2mm, sy=4mm, linewidth=.025mm, offset=.1mm,]

xsized 8cm;
\stopMPcode
\stoptext

But I didn't find anywhere in manuals or the mailing list concerning arrows, nor key-value pairs for lmt_function. Thank you in advance.

Best regards,

Jairo :)