[R] can not extract rows which match a string

[Rui Barradas]

Hello,

Then it's easier, is.na alone will do it.

j <- is.na(t1$sex_chromosome_aneuploidy_f22019_0_0)
t1[j, ]


Hope this helps,

Rui Barradas


Às 20:29 de 03/10/19, Ana Marija escreveu:
> Hi Rui,
> 
> sorry for confusion, I would only need to extract from my t1 dataframe
> rows which have NA in sex_chromosome_aneuploidy_f22019_0_0
> in other words to REMOVE rows with "Yes" and to keep rows with NA. How
> to do that?
> 
> On Thu, Oct 3, 2019 at 2:26 PM Rui Barradas <ruipbarradas using sapo.pt> wrote:
>>
>> Hello,
>>
>> You have to use is.na to get the NA values.
>>
>>
>> t1 <- data.frame(sex_chromosome_aneuploidy_f22019_0_0 = c(NA, "Yes"),
>>                    other = 1:2)
>>
>> i <- t1$sex_chromosome_aneuploidy_f22019_0_0 == "Yes" &
>> !is.na(t1$sex_chromosome_aneuploidy_f22019_0_0)
>> i
>> t1[i, ]
>>
>>
>> Hope this helps,
>>
>> Rui Barradas
>>
>> Às 19:58 de 03/10/19, Ana Marija escreveu:
>>> Hello,
>>>
>>> I have a dataframe (t1) with many columns, but the one I care about it this:
>>>> unique(t1$sex_chromosome_aneuploidy_f22019_0_0)
>>> [1] NA    "Yes"
>>>
>>> it has these two values.
>>>
>>> I would like to remove from my dataframe t1 all rows which have "Yes"
>>> in t1$sex_chromosome_aneuploidy_f22019_0_0
>>>
>>> I tried selecting those rows with "Yes" via:
>>>
>>> t11=t1[t1$sex_chromosome_aneuploidy_f22019_0_0=="Yes",]
>>>
>>> but I got t11 which has the exact same number of rows as t1.
>>>
>>> If I do:
>>>> table(t1$sex_chromosome_aneuploidy_f22019_0_0)
>>>
>>> Yes
>>> 620
>>>
>>> So there is for sure 620 rows which have "Yes". How to remove those
>>> from my t1 data frame?
>>>
>>> Thanks
>>> Ana
>>>
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