I am trying to represent seasonal tendencies of low flow events in
streamflow data. I have used days of the year (1:365) to describe the day
on which the lowest flow occurs. Within years there are often ties, and
they are often in winter, such that I may get 364,365,1,2 as the vector of
yeardays. Taking the mean or the median of these is 183, which is clearly
not what I want, since it represents a date in summer. The same problem
exists among years, since the low flow may be on day 365 in one year and day
1 in another year. Is there a simple way to make these circular, such that
yearday 365 is next to yearday 1?
I'm using Splus 6.2, Win XP
Many thanks, Todd Hatfield
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