Read a .DAT file that looks like a sparse matrix in r

0
votes

I have a .DAT file that contains several thousand rows of data. Each row has a fixed number of variables and each row is a case, but not every case has values for each variable. So if a case doesn't have a value for a variable, that space will be blank. So the entire data looks like a sparse matrix. A sample data looks like below:

10101010  100  10000FM

001 100 100  1000000 F

I want to read this data in r as a data frame. I've tried read.table but failed. My code is 

m <- read.table("C:/Users/Desktop/testdata.dat", header = FALSE)

R gives me error message like

"Error in scan(file = file, what = what, sep = sep, quote = quote, dec = dec, : line 1 did not have 6 elements"

How do I fix this?

1
rmatrixsparse-matrix
It sounds like you have a fixed-width file. Here's a duplicate thread on SO on using read.fwf. Maybe only difference is that you have widths=1 for 1-character fields? Hope it helps. – ravic_

1 Answers

0
votes

Generally the dat file has some lines of extra information before actual data.

Skip them with the skip argument as follows:

df<-read.table("C:/Users/Desktop/testdata.dat",header=FALSE, skip=3)

Else you can also try the below using the readlines function, this will read the specified number of lines from your file (pass n parameter as below):

readLines("C:/Users/Desktop/testdata.dat",n=5)