[Rd] Depending on many packages: another best practice question

[hadley wickham]

Dear all,

ggplot currently requires 13 packages (grid, reshape, RColorBrewer,
proto, splines, MASS, Hmisc, boot, butler, hexbin, mapproj, quantreg,
sm).  Some of these are absolutely necessary (eg. proto), but most are
used for one or two specific tasks (eg. boot is only used to get
plogis, used for logit scales).

Do you think I should make them all "depends" packages, or "suggests"
packages, and then manually test for package presence before using a
certain function?  What is easier for users?

Thanks,

Hadley