Creates a scatterplot of the annual observed and simulated
peaks, calculated for each available water year of data
within the two series provided; note that the difference between this and
the annual.peak function is that here the peak event simulated for the same
day as the peak event in observed data is used, instead of the largest
recorded simulated event. In some sense this captures the timing of the
event, i.e. the peak event must be simulated on the same day as the observed
peak to be captured well.
The sim and obs should be of time series (xts) format and are assumed to be
of the same length and time period. The flow series are assumed to be daily
flows with units of m3/s.
The R2 diagnostic is calculated for a fit with no intercept (in a perfect
fit the points are identical, and intercept is automatically zero).
Note that a plot title is purposely omitted in order to allow the automatic
generation of plot titles.