You definitely cannot do out of bounds indexing of array parameters
for reading
in the 2D/3D scripts.
But you absolutely can do the following in the parameter script:
if max (gs_sh, gs_sho, gs_shu) > vardim2(gs_horGridY) then
parameters gs_horGridY[1][max (gs_sh, gs_sho, gs_shu)] = 0
parameters gs_horGridBegX[1][max (gs_sh, gs_sho, gs_shu)] = 0
parameters gs_horGridEndX[1][max (gs_sh, gs_sho, gs_shu)] = 0
endif
(the code snipplet is from the standard German AC windows)
In other words: you can extend your array parameters by simply setting the last item to create.
Decreasing the size of the array (which is a much rarer need) can be done by creating a new smaller array, copying the necessary values and setting the array parameter to the new array using the PARAMETERS command.
Zsolt Táskai
ArchiCAD Development - GDL Team
AC13, AC14 and upwards...