Issue when importing dataset: `Error in scan(...): line 1 did not have 145 elements`

import, r, read.table

Solution

This error is pretty self-explanatory. There seem to be data missing in the first line of your data file (or second line, as the case may be since you're using `header = TRUE`).

Here's a mini example:

## Create a small dataset to play with
cat("V1 V2\nFirst 1 2\nSecond 2\nThird 3 8\n", file="test.txt")

R automatically detects that it should expect rownames plus two columns (3 elements), but it doesn't find 3 elements on line 2, so you get an error:

read.table("test.txt", header = TRUE)
# Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings,  : 
#   line 2 did not have 3 elements

Look at the data file and see if there is indeed a problem:

cat(readLines("test.txt"), sep = "\n")
# V1 V2
# First 1 2
# Second 2
# Third 3 8

Manual correction might be needed, or we can assume that the value first value in the "Second" row line should be in the first column, and other values should be `NA`. If this is the case, `fill = TRUE` is enough to solve your problem.

read.table("test.txt", header = TRUE, fill = TRUE)
#        V1 V2
# First   1  2
# Second  2 NA
# Third   3  8

R is also smart enough to figure it out how many elements it needs even if rownames are missing:

cat("V1 V2\n1\n2 5\n3 8\n", file="test2.txt")
cat(readLines("test2.txt"), sep = "\n")
# V1 V2
# 1
# 2 5
# 3 8
read.table("test2.txt", header = TRUE)
# Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings,  : 
#   line 1 did not have 2 elements
read.table("test2.txt", header = TRUE, fill = TRUE)
#   V1 V2
# 1  1 NA
# 2  2  5
# 3  3  8

Problem

Original source