?filter perhaps.
-- Bert On Wed, Nov 13, 2013 at 1:10 PM, Adams, Jean <jvad...@usgs.gov> wrote: > On Tue, Nov 12, 2013 at 11:45 AM, umair durrani > <umairdurr...@outlook.com>wrote: > >> I am new to R and have already posted this question on stack overflow. The >> problem is that I did not understand the answers as the R documentation >> about the discussed functions (e.g. 'convolve') is quite complicated for a >> newbie like me. Here's the question: >> I have a big text file with more than 3 million rows. The following is the >> example of the three columns I want to use: >> indx vehID LocalY >> 1 2 35.381 >> 2 2 39.381 >> 3 2 43.381 >> 4 2 47.38 >> 5 2 51.381 >> 6 2 55.381 >> 7 2 59.381 >> 8 2 63.379 >> 9 2 67.383 >> 10 2 71.398 >> where,indx = IndexvehID = Vehicle ID (Here only '2' is shown but infact >> there are 2169 vehicle IDs and each one repeats several times because the >> data was collected at every 0.1 seconds)LocalY = The y coordinate of the >> vehicle at a particular time (The time column is not shown here) >> What I want to do is to create a new column of 'SmoothedY' using the >> following formula: >> SmoothedY = 1/Z * Summation from (i-15) to (i+15) (LocalY * >> exp(-abs(i-k))/5)) >> where,i = indxZ = Summation from (k =i-15) to (k = i+15) ( >> exp(-abs(i-k))/5)) >> How can I apply this formula to create the new column 'SmoothedY'? This is >> actually a data smoothing problem but default smoothing algorithms in R are >> not suitable for my data and I have to use this custom formula. >> Thanks in advance. >> >> Umair Durrani >> > > I have never tried this myself, but it appears as if you can define your > own smoothing function using Simon Wood's mgcv package. Check out > http://www.maths.bath.ac.uk/~sw283/talks/snw-R-talk.pdf for more > information. > > Jean > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. -- Bert Gunter Genentech Nonclinical Biostatistics (650) 467-7374 ______________________________________________ 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.