Remove Rows From Data Frame where a Row matches a String
RDataframeR Problem Overview
I do I remove all rows in a dataframe where a certain row meets a string match criteria?
For example:
A,B,C
4,3,Foo
2,3,Bar
7,5,Zap
How would I return a dataframe that excludes all rows where C = Foo:
A,B,C
2,3,Bar
7,5,Zap
R Solutions
Solution 1 - R
Just use the == with the negation symbol (!). If dtfm is the name of your data.frame:
dtfm[!dtfm$C == "Foo", ]
Or, to move the negation in the comparison:
dtfm[dtfm$C != "Foo", ]
Or, even shorter using subset():
subset(dtfm, C!="Foo")
Solution 2 - R
You can use the dplyr package to easily remove those particular rows.
library(dplyr)
df <- filter(df, C != "Foo")
Solution 3 - R
I had a column(A) in a data frame with 3 values in it (yes, no, unknown). I wanted to filter only those rows which had a value "yes" for which this is the code, hope this will help you guys as well --
df <- df [(!(df$A=="no") & !(df$A=="unknown")),]
Solution 4 - R
if you wish to using dplyr, for to remove row "Foo":
df %>%
filter(!C=="Foo")
Solution 5 - R
I know this has been answered but here is another option:
library (dplyr)
df %>% filter(!c=="foo)
OR
df[!df$c=="foo", ]
Solution 6 - R
If your exclusion conditions are stored in another data frame you could use rows_delete:
library(dplyr)
removal_df <- data.frame(C = "Foo")
df %>%
rows_delete(removal_df, by = "C")
A B C
1 2 3 Bar
2 7 5 Zap
This is also handy if you have multiple exclusion conditions so you do not have to write out a long filter statement.
Note: rows_delete is only available if you have dplyr >= 1.0.0