Dear all-
I have a data set that looks as follows (data are taken every 5 minutes):
LST in mph Deg DegF DegF2 % volts Deg mph2 w/m2
0905010000 -999 7.5 259.3 33.0 -999 41.5 -999 -999 9.1 0.2
0905010005 -999 11.0 261.2 33.1 -999 42.6 -999 -999 18.2 0.2
0905010010 -999 8.9 252.5 33.4 -999 41.6 -999 -999 12.4 0.2
0905010015 -999 9.1 265.9 33.2 -999 41.8 -999 -999 11.7 0.2
I am able to calculate the hourly average of "mph" over a span of 3
months with the following code:
z <- read.zoo("SPL summer 2009.txt", header = TRUE, na.strings =
-999,
format = "%y%m%d%H%M", FUN = as.chron,
colClasses = c("character", rep("numeric", 10)))
mph <- z[months(time(z)) %in% c("May", "Jun",
"Jul"),]
ww <- aggregate(z$mph, trunc(time(z), "hour"), mean)
but, i need to take the hourly average (spanning the same three months) of the
directional degrees (Deg) in order to use that data to create a wind rose. I
was planning to get the hourly avg step by step , i.e. converting to radians,
taking sins, etc, but "aggregate" seems to only use summary-type
functions. I have been playing around with "daply", which seems to
accept other functions, but am not sure how to convert the time/date stamp
within it.
I would appreciate it if anyone could point me in the right direction-
sherri
On Tue, Aug 18, 2009 at 7:09 PM, Sherri Heck<sheck at ucar.edu> wrote:> Dear all- > > I have a data set that looks as follows (data are taken every 5 minutes): > > ? ? ?LST ? in ? ? mph ? ?Deg ? DegF ?DegF2 ? ?% ? ?volts ? Deg ? ?mph2 ? w/m2 > 0905010000 ? -999 ? ?7.5 ?259.3 ? 33.0 ? -999 ? 41.5 ? -999 ? -999 ? ?9.1 ? ?0.2 > 0905010005 ? -999 ? 11.0 ?261.2 ? 33.1 ? -999 ? 42.6 ? -999 ? -999 ? 18.2 ? ?0.2 > 0905010010 ? -999 ? ?8.9 ?252.5 ? 33.4 ? -999 ? 41.6 ? -999 ? -999 ? 12.4 ? ?0.2 > 0905010015 ? -999 ? ?9.1 ?265.9 ? 33.2 ? -999 ? 41.8 ? -999 ? -999 ? 11.7 ? ?0.2 > > > I am able to calculate the hourly average of "mph" over a span of 3 months with the following code: > > > z <- read.zoo("SPL summer 2009.txt", header = TRUE, na.strings = -999, > format = "%y%m%d%H%M", FUN = as.chron, > colClasses = c("character", rep("numeric", 10))) > mph <- z[months(time(z)) %in% c("May", "Jun", "Jul"),] > ww <- aggregate(z$mph, trunc(time(z), "hour"), mean) > > > but, i need to take the hourly average (spanning the same three months) of the directional degrees (Deg) in order to use that data to create a wind rose. ?I was planning to get the hourly avg step by step , i.e. ?converting to radians, taking sins, etc, but "aggregate" seems to only use summary-type functions. ?I have been playing around with "daply", which seems to accept other functions, but am not sure how to convert the time/date stamp within it. >You can aggregate by any function that inputs a vector and produces a scalar. Can you clarify what function you want to aggregate by that you believe cannot be handled?
On Wed, Aug 19, 2009 at 12:14 AM, Gabor Grothendieck<ggrothendieck at gmail.com> wrote:> On Tue, Aug 18, 2009 at 7:09 PM, Sherri Heck<sheck at ucar.edu> wrote: >> Dear all- >> >> I have a data set that looks as follows (data are taken every 5 minutes): >> >> ? ? ?LST ? in ? ? mph ? ?Deg ? DegF ?DegF2 ? ?% ? ?volts ? Deg ? ?mph2 ? w/m2 >> 0905010000 ? -999 ? ?7.5 ?259.3 ? 33.0 ? -999 ? 41.5 ? -999 ? -999 ? ?9.1 ? ?0.2 >> 0905010005 ? -999 ? 11.0 ?261.2 ? 33.1 ? -999 ? 42.6 ? -999 ? -999 ? 18.2 ? ?0.2 >> 0905010010 ? -999 ? ?8.9 ?252.5 ? 33.4 ? -999 ? 41.6 ? -999 ? -999 ? 12.4 ? ?0.2 >> 0905010015 ? -999 ? ?9.1 ?265.9 ? 33.2 ? -999 ? 41.8 ? -999 ? -999 ? 11.7 ? ?0.2 >> >> >> I am able to calculate the hourly average of "mph" over a span of 3 months with the following code: >> >> >> z <- read.zoo("SPL summer 2009.txt", header = TRUE, na.strings = -999, >> format = "%y%m%d%H%M", FUN = as.chron, >> colClasses = c("character", rep("numeric", 10))) >> mph <- z[months(time(z)) %in% c("May", "Jun", "Jul"),] >> ww <- aggregate(z$mph, trunc(time(z), "hour"), mean) >> >> >> but, i need to take the hourly average (spanning the same three months) of the directional degrees (Deg) in order to use that data to create a wind rose. ?I was planning to get the hourly avg step by step , i.e. ?converting to radians, taking sins, etc, but "aggregate" seems to only use summary-type functions. ?I have been playing around with "daply", which seems to accept other functions, but am not sure how to convert the time/date stamp within it. >> > > You can aggregate by any function that inputs a vector and produces > a scalar. ?Can you clarify what function you want to aggregate by that you > believe cannot be handled? >Just to finish off this thread what turned out to be wanted was this slight variation of the original code: aggregate(sin(z$Deg * pi / 180), trunc(time(z), "hour"), mean)