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
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