[gembud] GFUNC Question

[Jeffrey Krob - NOAA Federal <jeffrey.a.krob@xxxxxxxx>]

 Hello & Happy New Year!

I came across a GFUNC script dealing with the calculation of Slantwise
CAPE. One of the scripts is as follows:

GFUNC =
'mul(acos(quo(mul(mag(vasv(vecr(urel,0),geo)),quo(urel,mag(vecr(urel,0)))),urel)),RTD)'

My question concerns wanting to understand the specific command
'vecr(urel,0)'- is this actually collecting only the 'U' portion the of the
U/V vector pair (ignoring the 'V' portion) or is something else happening
here?

Thanks in advance,
Jeff