Read.table problems

Dear all,

I have a file which I've converted from NetCDF (.nc) to text (.txt)  
using ncdump in Unix (as I had problems using the ncdf package to do  
this). The first few rows (as copied and pasted from the Unix  
console) of the file appear as follows:

_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,
   _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _,


As you can see, there are a lot of NA values before the actual  
numeric values start further down the dataset. My problem is that  
I'm having trouble reading this file into R. I think the problem  
lies with the sep= argument, although I may be wrong. I tried the  
following command at first, as the data appear to be comma separated:

read.table("test86.txt", skip=43, na.strings="-", header=FALSE,  
sep=",") -> test86  # skip =43 due to meta-data information being  
held in the initial rows

Error in scan(file, what, nmax, sep, dec, quote, skip, nlines,  
na.strings,  :
 line 29 did not have 25 elements

I then tried sep=" ", followed by sep="" but received a similar-type  
error message (although line 29 doesn't appear to be especially  
different from the rest).

I subsequently tried using sep=\t and then sep=\n. These both result  
in the data being read in without an error message being displayed,  
although the data are formatted as follows:

head(test86)

                                                                           V1
1     _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _, _,
2     _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _, _,
3     _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _, _,
4     _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _, _,
5     _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _, _,
6     _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _,  
_, _, _,

dim(test86)

[1] 179899      1


Instead of one column, I'd expect there to be 720.


I think I'm getting something wrong relating to the sep= argument  
(or possibly mis-using na.strings?). If anyone has any solutions to  
this then I'd be very grateful to hear them.

Many thanks for any advice,

Steve