I have files containing data sets which contain 11,000 rows. I have to run a loop through each row, which is taking me 25 minutes for each file.     z <- read.zoo(Title.txt, tz = )  for(i in seq_along(z[,1])) {    if(is.na(coredata(z[i,1]))) next   ctr <- i    while(ctr < length(z[,1])) {     if(       (   abs  ( coredata(z[i,1]) -coredata(z[ctr+1,1])  )      )  > std_d) {       z[ctr+1,1] <- NA       ctr <- ctr + 1      } else {  break    } }}Where Title.txt is a file containing 11,000 rows. It looks like this (first five rows):timestamp mesured_distance IFC_Code from_sensor_to_river_bottom 1 2012-06-03 12:30:07-05 3188 1005 3500 2 2012-06-03 12:15:16-05 3189 1005 3500 3 2012-06-03 12:00:08-05 3185 1005 3500 4 2012-06-03 11:45:11-05 3191 1005 3500 5 2012-06-03 11:30:15-05 3188 1005 3500How can I increase the speed of this code?
Looping through rows of data sets in files
performance;r