(TRUE/FALSE) check for projection integrity and
calculate central latitude for non-geographic
projections
force.hemisphere
If country is split at the equator, force southern
or northern hemisphere equation c("southern", "northern")
Value
raster class object of McCune & Keon (2002) Heat Load Index
References
McCune, B., and D. Keon (2002) Equations for potential annual direct
incident radiation and heat load index. Journal of Vegetation
Science. 13:603-606.
McCune, B. (2007). Improved estimates of incident radiation and heat load
using non-parametric regression against topographic variables. Journal
of Vegetation Science 18:751-754.