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I would like to combine three columns in one of my data sets into one with variable name "al_anim" and remove any duplicates, rank the values (animal ids) from lowest to highest, and re-number each animal from 1 to N under the variable name "new_id".
anim1 <- c(1456,2569,5489,1456,4587)
anim2 <- c(6531,6987,6987,15487,6531)
anim3 <- c(4587,6548,7894,3215,8542)
mydf <- data.frame(anim1,anim2,anim3)
Any help would be very much appreciated!
Baz
869
Convert multiple columns into a single column, To combine numerous data frame columns into one column, use the union() function from the tidyr package.
Use select() function from dplyr package to reorder or change the order of columns in R, to use select() function, you have to install dplyr first using install. packages('dplyr') and load it using library(dplyr) . All functions in dplyr package take data.
To join data frames on multiple columns in R use either base merge() function or use dplyr functions. Using the dplyr functions is the best approach as it runs faster than the R base approach. dplyr package provides several functions to join R data frames and all these supports joining on multiple columns.
How do I concatenate two columns in R? To concatenate two columns you can use the <code>paste()</code> function. For example, if you want to combine the two columns A and B in the dataframe df you can use the following code: <code>df['AB'] <- paste(df$A, df$B)</code>.
Using mydf from your example:
mydf <- data.frame(anim1, anim2, anim3)
Stack the data:
sdf <- stack(mydf)
Then compute the unique elements using unique()
uni <- unique(sdf[, "values"])
and then this will get them a new animal id
new_id <- as.numeric(as.factor(sort(uni)))
which would give:
> new_id
[1] 1 2 3 4 5 6 7 8 9 10 11
However that is totally trivial; seq_along(uni) gets you there far more easily. So I wonder if you want
newdf <- data.frame(anim = sort(uni), new_id = seq_along(uni))
merge(sdf, newdf, by.x = "values", by.y = "anim")
which gives:
> merge(sdf, newdf, by.x = "values", by.y = "anim")
values ind new_id
1 1456 anim1 1
2 1456 anim1 1
3 2569 anim1 2
4 3215 anim3 3
5 4587 anim1 4
6 4587 anim3 4
7 5489 anim1 5
8 6531 anim2 6
9 6531 anim2 6
10 6548 anim3 7
11 6987 anim2 8
12 6987 anim2 8
13 7894 anim3 9
14 8542 anim3 10
15 15487 anim2 11
There is an amount of ambiguity in your Question which could be alleviated by giving an expected result/output.
158
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