[R] "invalid argument to unary operator" while selecting rows by name

[Pauline Laïlle]

Dear all,

I built a dataframe with read.csv2(). Initially, row names are integers
(order of answers to a survey). They are listed in the csv's first column.
The import works well and my dataframe looks like I wanted it to look.

Row names go as follows :
 [1] "6"   "29"  "31"  "32"  "52"  "55"  "63"  "71"  "72"  "80"  "88"  "89"
 "91"  "93"  "105" "110" "111" "117" "119" "120"
 [21] "122" "127" "128" "133" "137" "140" "163" "165" "167" "169" "177"
"178" "179" "184" "186" "192" "193" "200" "201" "228"
etc.

I would like to drop rows "601" & "604" to clean the dataframe.

While data["601",] shows me the first row i'd like to drop, data[-"601",]
returns the following :
Error in -"601" : invalid argument to unary operator

idem with data[c("601","604"),] and data[-c("601","604"),]

It is the first time that I run into this specific error. After reading a
bit about it I still don't understand what it means and how to fix it.

Thanks for reading!
Best,
Pauline.

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