Each R package should include ../../math/R/Makefile.extension, which also
defines MASTER_SITES. Consequently, it is redundant for the individual
packages to do the same. Package-specific definitions also prevent
redefining MASTER_SITES in a single common place.
Methods for calculating (usually) accurate numerical first and second
order derivatives. Accurate calculations are done using 'Richardson”s'
extrapolation or, when applicable, a complex step derivative is
available. A simple difference method is also provided. Simple
difference is (usually) less accurate but is much quicker than
'Richardson”s' extrapolation and provides a useful cross-check.
Methods are provided for real scalar and vector valued functions.
