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I have a dataframe like this:
V1 V2 V3
1 1 3423086 3423685
2 1 3467184 3467723
3 1 4115236 4115672
4 1 5202437 5203057
5 2 7132558 7133089
6 2 7448688 7449283
I want to change the V1 column and add chr before the number. Just like this:
V1 V2 V3
1 chr1 3423086 3423685
2 chr1 3467184 3467723
3 chr1 4115236 4115672
4 chr1 5202437 5203057
5 chr2 7132558 7133089
6 chr2 7448688 7449283
Is there a way to do this in R?
507
Append a character or string to start of the column in pandas: Appending the character or string to start of the column in pandas is done with “+” operator as shown below.
To add a new column to a dataframe in R you can use the $-operator. For example, to add the column “NewColumn”, you can do like this: dataf$NewColumn <- Values . Now, this will effectively add your new variable to your dataset.
append() function is used to append rows of other dataframe to the end of the given dataframe, returning a new dataframe object. Columns not in the original dataframes are added as new columns and the new cells are populated with NaN value. Parameters: other : DataFrame or Series/dict-like object, or list of these.
The regex pattern "^" (outside any character-class brackets) represents the point just before the first character of a "character"-class item (aka "string" in other computer languages). This just replaces the beginning of each "character" element in vector with a stem of "chr". It implicitly coerces a "numeric" input value to "character" so alters the mode of the result.
> dat$V1 <- sub("^", "chr", dat$V1 )
> dat
V1 V2 V3
1 chr1 3423086 3423685
2 chr1 3467184 3467723
3 chr1 4115236 4115672
4 chr1 5202437 5203057
5 chr2 7132558 7133089
6 chr2 7448688 7449283
Could, of course, have used paste("chr", dat$V1, sep=""), but I thought a regex solution might be neater.
147
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