R: importing multiple files [duplicate] - r

Question

This question already has answers here:
Importing many files at the same time and adding ID indicator
(2 answers)
Closed 4 years ago.
I have data that is save with .log extension. The content of the file looks like:
Trajectory Log File
Date: Sun Mar 04 15:32:29 2018
Nr of Trajectories: 91
Trajectory-Mode: ON
Average Slope (Degrees): 28.05 / 51.99 / 64.83
Filename: test_tschamut_Pos1.xml
Z-offset: 1.32000
Rock Position X: 696621.38
Rock Position Y: 167730.02
Rock Position Z: 1679.6400
Friction:
Overall Type: Medium
t (s) x (m) y (m) z (m) p0 () p1 () p2 () p3 () vx (m s-1) vy (m s-1) vz (m s-1) wx (rot s-1) wy (rot s-1) wz (rot s-1) Etot (kJ) Ekin (kJ) Ekintrans (kJ) Ekinrot (kJ) zt (m) Fv (kN) Fh (kN) Slippage (m) mu_s (N s m-1) v_res (m s-1) w_res (rot s-1) JumpH (m) ProjDist (m) Jc () JH_Jc (m) SD (m)
0.000 696621.380 167730.020 1680.960 1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1192.526 0.000 0.000 0.000 1677.754 0.000 0.000 0.000 0.350 0.000 0.000 3.206 0.000 0.000 0.000 0.000
0.010 696621.380 167730.020 1680.959 1.000 0.000 -0.000 0.000 0.000 0.000 -0.098 0.000 0.000 0.000 1192.526 0.010 0.010 0.000 1677.754 0.000 0.000 0.000 0.350 0.098 0.000 3.205 0.000 0.000 0.000 0.000
0.020 696621.380 167730.020 1680.958 1.000 0.000 -0.000 0.000 0.000 0.000 -0.196 0.000 0.000 0.000 1192.526 0.039 0.039 0.000 1677.754 0.000 0.000 0.000 0.350 0.196 0.000 3.204 0.000 0.000 0.000 0.000
0.040 696621.380 167730.020 1680.952 1.000 0.000 -0.000 0.000 0.000 0.000 -0.392 0.000 0.000 0.000 1192.526 0.158 0.158 0.000 1677.754 0.000 0.000 0.000 0.350 0.392 0.000 3.198 0.000 0.000 0.000 0.000
0.060 696621.380 167730.020 1680.942 1.000 0.000 -0.000 0.000 0.000 0.000 -0.589 0.000 0.000 0.000 1192.526 0.355 0.355 0.000 1677.754 0.000 0.000 0.000 0.350 0.589 0.000 3.188 0.000 0.000 0.000 0.000
0.080 696621.380 167730.020 1680.929 1.000 0.000 -0.000 0.000 0.000 0.000 -0.785 0.000 0.000 0.000 1192.526 0.631 0.631 0.000 1677.754 0.000 0.000 0.000 0.350 0.785 0.000 3.175 0.000 0.000 0.000 0.000
0.110 696621.380 167730.020 1680.901 1.000 0.000 -0.000 0.000 0.000 0.000 -1.079 0.000 0.000 0.000 1192.526 1.193 1.193 0.000 1677.754 0.000 0.000 0.000 0.350 1.079 0.000 3.147 0.000 0.000 0.000 0.000
0.130 696621.380 167730.020 1680.877 1.000 0.000 -0.000 0.000 0.000 0.000 -1.275 0.000 0.000 0.000 1192.526 1.666 1.666 0.000 1677.754 0.000 0.000 0.000 0.350 1.275 0.000 3.123 0.000 0.000 0.000 0.000
0.150 696621.380 167730.020 1680.850 1.000 0.000 -0.000 0.000 0.000 0.000 -1.472 0.000 0.000 0.000 1192.526 2.218 2.218 0.000 1677.754 0.000 0.000 0.000 0.350 1.472 0.000 3.096 0.000 0.000 0.000 0.000
0.160 696621.380 167730.020 1680.834 1.000 0.000 -0.000 0.000 0.000 0.000 -1.570 0.000 0.000 0.000 1192.526 2.523 2.523 0.000 1677.754 0.000 0.000 0.000 0.350 1.570 0.000 3.080 0.000 0.000 0.000 0.000
0.180
How can i import this data format in R ?
Is it possible to import many files of this format at the same time?
thanks!

Answer 1

You can read the tabular part using read.table or read.fwf with skip=N (where N is the number of lines before table's header). Then you can read the first N lines with readLines and extract the parts you need.
For exporting many files with the same format, I suggest you start with writing a function combining all the steps, something like this:
read.log <- function(filename){
first <- readLines(filename, 10)
date <- sub("Date: ", "", first[2]) # get date from second row
date <- as.POSIXct(date, format="?strptime") # convert to date
# use ?strptime to see how to specify date format
# .... likewise for other pieces eg. nr. of trajectories
second <- read.table(filename, skip = 10) # some other no. instead of 10
R <- list(data=second, date=date, otherstuff = otherstuff, ...)
# return as a list
R
}
Now you can use this function to read in any file, or apply it to a list of file names (using lapply or a for loop).