Dear All,
I have several sets of data such as this:
?year jday ?avg_m3s
1 1960 ? ?1 4.262307
2 1960 ? ?2 4.242308
3 1960 ? ?3 4.216923
4 1960 ? ?4 4.185385
5 1960 ? ?5 4.151538
6 1960 ? ?6 4.133846
?...
There is a value for each day of multiple years. In this particular data set it goes up to 1974. I am am looking to obtain the minimum and maximum values for each year, but also know on which julian day ("jday") they occurred.
I can get the maximum value for each year with:
mx = aggregate(ddat$avg_m3s, list(Year=ddat$year), max, na.rm=T)
colnames(mx) <- c("year","max_daily")
? year max_daily
1 ?1960 ?60.24615
2 ?1961 ?73.90000
3 ?1962 ?56.40000
...
But I want to output the max with the corresponding day on which it occurred, such as:
?year jday ?avg_m3s
1 1960 ? ?136 60.24615
2 1961 ? ?129 73.90000
3 1962 ? ?111 56.40000
I haven't been able to determine how to keep those ties without aggregating by both year *and day, which is what happened with:
aggregate(ddat$avg_m3s, list(Year=ddat$year, Day = ddat$jday), max, na.rm=T),
resulting in a value output for every single day of each year.
Other attempts to get both columns to output failed.
Any help would be greatly appreciated!
Kara