Update: I have this so far. * The first column of windHW is the wind speed. The 5th column of the dataframe, spring, is the 5*sigma value of every hour. hourRow gives out all the rows of wind speed at a given hour.
for (i in 0:23){ hourRow = which(windHW$hour==i,arr.ind=TRUE) for (h in hourRow){ if (windHW[h,1]>=spring[spring$hour==i,5]){ windHW[h,1]<-NA} } } This then gives the error: Error in if (windHW[h, 1] >= spring[spring$hour == i, 5]) { : argument is of length zero *Note: The dataframe for each of the seasons have 24 rows corresponding to each hour of the day 0:23. Thanks, Alexandra On Fri, Apr 10, 2015 at 1:07 PM, Alexandra Catena <amc5...@gmail.com> wrote: > Hello, > > I have a large dataframe (windHW) of wind speeds (ws) at each hour > from many days over a set of years. Some of these values are > obviously wrong (600 m/s) and I want to get rid of all the values that > are larger than 5*sigma for each hour. The 5*sigma (variable name > sigma5) values are located in different dataframes for each season, > with each dataframe titled as a season. For example, in the > dataframe, spring, the 5*sigma value is 79.6 m/s for hour 1. > > So my question is as follows: how can I get it so that the code will > be able to find all the wind speed values in the dataframe, windHW, of > a specific hour be higher than the 5*sigma value at that hour? > For example, I would like to find if any of the wind speed values at > hour 1 are higher than 79.6 m/s, and if so, then replace that value > with NA. > > I have something like this but I can't seem to figure out how to get > it for specific hours: > > windHW$ws[windHW$ws>=spring$sigma5] <- NA > > I imported the data using readLines and into the dataframe windHW. I > also have R version 3.1.1 > > Any help would be appreciated! > > Thanks, > Alexandra ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.