NetCDF User's Guide
The inner product of two vectors
[x0, x1, ..., xn] and [y0, y1, ..., yn] is just x0*y0 + x1*y1 + ... +
xn*yn.
A point's coordinate offset vector gives,
for each dimension, the offset from the origin of the containing array
to the point.
In C, a point's coordinate offset vector is the same as it's coordinate
vector.
In FORTRAN, however, the values of a point's coordinate offset vector
are one less than the corresponding values of the point's coordinate vector.