[Rd] read.csv, worrying behaviour?

Kevin R. Coombes kev|n@r@coombe@ @end|ng |rom gm@||@com
Thu Feb 25 18:50:02 CET 2021


I believe this is documented behavior. The 'read.csv' function is a 
front-end to 'read.table' with different default values. IN this 
particular case, read.csv sets fill = TRUE, which means that it is 
supposed to fill incomplete lines with NA's. It also sets header=TRUE, 
which is presumably what it is using to determine the expected length of 
a line-row.
   -- Kevin

On 2/25/2021 4:11 AM, TAYLOR, Benjamin (BLACKPOOL TEACHING HOSPITALS NHS 
FOUNDATION TRUST) via R-devel wrote:
> Dear all
>
> I've been using R for around 16 years now and I've only just become aware of a behaviour of read.csv that I find worrying which is why I'm contacting this list. A simplified example of the behaviour is as follows
>
> I created a "test.csv" file containing the following lines:
>
> a,b,c,d,e,f,g
> 1,2,3,4
>
> And then read it into R using:
>
>> d = read.csv("test.csv")
>> d
>    a b c d  e  f  g
> 1 1 2 3 4 NA NA NA
>
> I was surprised that this did not issue a warning. I can understand why the following csv would not issue a warning:
>
> a,b,c,d,e,f,g
> 1,2,3,4,,,
>
> But the missing commas in the first example? Thoughts from others would be welcome.
>
> Kind regards
>
> Ben
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Benjamin M. Taylor, MSci, MSc, PhD
> Lead Data Scientist
> Blackpool Teaching Hospitals NHS Foundation Trust
> Home 15
> Whinney Heys Road
> Blackpool
> FY3 8NR
>
> Scholar: https://scholar.google.co.uk/citations?user=6Hf0CJkAAAAJ&hl=en
> Github: https://github.com/bentaylor1
> Gitlab: https://gitlab.com/ben_taylor
> ORCID: http://orcid.org/0000-0001-8667-4089
>
>
>
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>
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