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

[ruipbarradas at sapo.pt]

Hello,

The error message means exactly what it says. The operator '-' is  
unary and cannot be followed by a non-numeric atomic object (a vector).
Try for instance

x <- list(a=1:10, b=rnorm(5))
-x

Rui Barradas
 

Citando Pauline Laïlle <pauline.laille at gmail.com>:

> Works like a charm, thanks! Still don't know what that error message  
> means though. Any idea?
>
>   2016-09-20 20:13 GMT+02:00 <ruipbarradas at sapo.pt>:
>> Sorry, I've made a stupid mistake.
>> It's obviously the other way around.
>>
>> ix <- which(rownames(data) %in% c("601", "604"))
>> clean <- data[-ix, ]
>>
>> Rui Barradas
>>
>> Citando ruipbarradas at sapo.pt:   
>>> Hello,
>>>
>>> Try something like the following.
>>>
>>> ix <- which(c("601", "604") %in% rownames(data))
>>> clean <- data[-ix, ]
>>>
>>> Hope this helps,
>>>
>>> Rui Barradas
>>>
>>> Citando Pauline Laïlle <pauline.laille at gmail.com>:
>>>  
>>>> 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.
>>>>
>>>>         [[alternative HTML version deleted]]
>>>>
>>>> ______________________________________________
>>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>> PLEASE do read the posting guide  
>>>> http://www.R-project.org/posting-guide.html
>>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide  
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>  

 

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