EOF output normalisation

In an Empirical Orthogobal Function (EOF) decomposition the
normalisation of the EOF maps and PC time series in arbitarry.
Consider the definition
*E*(*x*,*t*) = ∑_{i=1N
Ei(x) pi(t)
}

One can multiply the EOF *E _{i}*(

You can choose between four normalisation schemes.

- Spatial maximum one. This implies that all EOF plots will run
from -1 to +1, which makes them easy to plot. The PC time series
will have the units of the original field and smaller amplitudes for
higher values of EOF number
*i*. - Spatial variance one. resembles the previous option, but makes the EOFs and PCs more comparable if there are few isolated areas with large amplitude in the EOF.
- Time series maximum one. Not very useful, included for
symmtery.
*Time series variance one. This option implies that the EOF maps have the units of teh original field. They will have smaller amplitude for larger EOF number**i*.