32.4 Variable naming
The recommended variable naming is to follow C/C++ naming
conventions, in which variables are lowercase, with the underscore
_) used as a separator. Thus it is preferred to use
sigma_y, rather than the run together
sigmaY, or capitalized camel-case
SigmaY. Even matrix
variables should be lowercased.
The exception to the lowercasing recommendation, which also follows the C/C++ conventions, is for size constants, for which the recommended form is a single uppercase letter. The reason for this is that it allows the loop variables to match. So loops over the indices of an \(M \times N\) matrix \(a\) would look as follows.
for (m in 1:M) for (n in 1:N) a[m,n] = ...