[R] Trouble pulling data from a messy ASCII file...

[Sarah Goslee]

I usually use Unix tools to process really data beforehand (sed, awk), but
if you want a pure R solution it is usually possible to kludge
something together
with scan() working line by line.

# read a line
# if it contains stuff you aren't interested in, go on to the next line
# if it contains one kind of interesting stuff, do X
# if it contains another kind of interesting stuff, do Y

and so on.

I've done this when it was easier than alternative processing (though
slower), and
found that it worked best for  me to read the entire line in as a
string, then split it
apart later and convert to numeric if appropriate.

Sarah

On Wed, Dec 17, 2008 at 2:37 PM, Titan8883 <jplaney at gmail.com> wrote:
>
> Hi all,
>
> I am a new graduate student who is also new to R. I am ok with the basics,
> but the problem I am having right now seems beyond what I can do..so I am
> looking for advice. I am trying to pull data from flat ASCII files, but they
> do not have a "nice" structure so a simple "read.table" doesn't work. An
> example first half of a data file is below:
> ----------------------------------------------------------------------------------------------
> 19 c:/data/WF-100/2008/20080911/trk/20080911.013115.007.17.txt
> 10 s   name of program that wrote this file trkplt   name of program that
> wrote this file
> 10 GORDON   machine that generated this file   machine that generated this
> file
> 10     3.7 version of program
> 10     3.6 version of this data file
> 10    5.81 version of Universal Library
> 10 20081121.145730 when this file was written
> 10 Windows_XP   operating system used   operating system used
> *
> *       radar characteristics
> 11 WF-100
> 11 20000000  A/D rate, samples/second
> 11 7.5  bin width, m
> 11 800  nominal PRF, Hz
> 11  0.25  nominal pulse width, microsec
> 11 0  tuning, volts
> 11 3.19779  nominal wave length, cm
> -----------------------------------------------------------------------------------------------
> ..the file goes on from there...
>
> How would I go about getting this data into some kind of useful format? This
> is one of about 1000 files I will need to go through. I would ideally like
> to get these into a format with each data file as a row with columns for the
> various values with the description text removed(version of program, file
> version, tuning volts, etc...).
>
> I'm not looking for a cut and paste answer, but perhaps some direction on
> where I should start. I have only done basic .csv, table, and line inputs up
> until now.
>
> Thanks for any advice

-- 
Sarah Goslee
http://www.functionaldiversity.org