Tim Clark <mudiver1200 <at> yahoo.com> writes: > > I need some help in coming up with a function that will take two data sets, determine if a value is missing in > one, find a value in the second that was taken at about the same time, and substitute the second value in for > where the first should have been.
This is the type of job I would do with a database, not R (alone). The main advantage is that you have to do the cleanup job only once and can retrieve the data in a rather well-documented way later (it's possible with R, I know). >> Put the 5 minutes data into one table. I would two new columns giving the delta to the next value for easier linear interpolation, but that's secondary. Make sure to index the table. >> Put the 1 seconds data into another table, adding values rounded to 5 seconds, and giving these an index. >>From R/ODBC or with RSQLite, make a Join of all values in Table 1 that do have NULL values in the coordinates. If you do not want to do a linear interpolation, you could even do this within the database and SQL alone. >> Compute the linear interpolation, and write the data back into the database. If you want to be careful, you might mark the interpolated values in a separate field as "computed" When at a later time new data come in, you can run the procedure again without penalty. Dieter ______________________________________________ R-help@r-project.org mailing list 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.