如何聚合一列中的值以创建新列

Question

I have a data frame with many repeating values in certain columns. I would like to create a new columns with a new value for each unique entry in the column of interest. I have looked around in aggregation related questions on Stack Overflow and haven't quite found what I am looking for.

dput(head(example)) output is below.

structure(list(avecor = c(-0.929199786400515, -0.729228501795928, 
-0.431983639087243, -0.55088842103792, -0.978422379116014, -0.627856061946295
), miR = structure(c(9L, 5L, 6L, 2L, 8L, 4L), .Label = c("hsa-miR-107", 
"hsa-miR-193a-3p", "hsa-miR-28-5p", "hsa-miR-331-3p", "hsa-miR-362-3p", 
"hsa-miR-362-5p", "hsa-miR-429", "hsa-miR-590-5p", "hsa-miR-630"
), class = "factor"), mRNA = structure(c(1L, 2L, 2L, 3L, 3L, 
4L), .Label = c("IGF1R", "PRKCA", "TESK2", "THBS1", "TLN2", "VAV3"
), class = "factor")), row.names = c("hsa-miR-630:IGF1R", "hsa-miR-362-3p:PRKCA", 
"hsa-miR-362-5p:PRKCA", "hsa-miR-193a-3p:TESK2", "hsa-miR-590-5p:TESK2", 
"hsa-miR-331-3p:THBS1"), class = "data.frame")

                          avecor             miR  mRNA
hsa-miR-630:IGF1R     -0.9291998     hsa-miR-630 IGF1R
hsa-miR-362-3p:PRKCA  -0.7292285  hsa-miR-362-3p PRKCA
hsa-miR-362-5p:PRKCA  -0.4319836  hsa-miR-362-5p PRKCA
hsa-miR-193a-3p:TESK2 -0.5508884 hsa-miR-193a-3p TESK2
hsa-miR-590-5p:TESK2  -0.9784224  hsa-miR-590-5p TESK2
hsa-miR-331-3p:THBS1  -0.6278561  hsa-miR-331-3p THBS1
hsa-miR-28-5p:TLN2    -0.9988643   hsa-miR-28-5p  TLN2
hsa-miR-331-3p:TLN2   -0.8773624  hsa-miR-331-3p  TLN2
hsa-miR-429:TLN2      -0.9901250     hsa-miR-429  TLN2
hsa-miR-107:VAV3      -0.7713383     hsa-miR-107  VAV3

If applied to the mRNA column, the ideal output would be:

                          avecor             miR  mRNA UniquemRNA
hsa-miR-630:IGF1R     -0.9291998     hsa-miR-630 IGF1R 1 
hsa-miR-362-3p:PRKCA  -0.7292285  hsa-miR-362-3p PRKCA 2
hsa-miR-362-5p:PRKCA  -0.4319836  hsa-miR-362-5p PRKCA 2
hsa-miR-193a-3p:TESK2 -0.5508884 hsa-miR-193a-3p TESK2 3
hsa-miR-590-5p:TESK2  -0.9784224  hsa-miR-590-5p TESK2 3
hsa-miR-331-3p:THBS1  -0.6278561  hsa-miR-331-3p THBS1 4
hsa-miR-28-5p:TLN2    -0.9988643   hsa-miR-28-5p  TLN2 5
hsa-miR-331-3p:TLN2   -0.8773624  hsa-miR-331-3p  TLN2 5
hsa-miR-429:TLN2      -0.9901250     hsa-miR-429  TLN2 5
hsa-miR-107:VAV3      -0.7713383     hsa-miR-107  VAV3 6

Any help would be most appreciated.

Answer 1

If I understand you correctly, you did already create that column by creating mRNA as a factor . If that is really what you want, you could just recode the factor into numeric values. But that does just replicate the information that is already there. This is how you could go about doing that:

library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
structure(list(avecor = c(-0.929199786400515, -0.729228501795928, 
                          -0.431983639087243, -0.55088842103792, -0.978422379116014, -0.627856061946295
), miR = structure(c(9L, 5L, 6L, 2L, 8L, 4L), .Label = c("hsa-miR-107", 
                                                         "hsa-miR-193a-3p", "hsa-miR-28-5p", "hsa-miR-331-3p", "hsa-miR-362-3p", 
                                                         "hsa-miR-362-5p", "hsa-miR-429", "hsa-miR-590-5p", "hsa-miR-630"
), class = "factor"), mRNA = structure(c(1L, 2L, 2L, 3L, 3L, 
                                         4L), .Label = c("IGF1R", "PRKCA", "TESK2", "THBS1", "TLN2", "VAV3"
                                         ), class = "factor")), row.names = c("hsa-miR-630:IGF1R", "hsa-miR-362-3p:PRKCA", 
                                                                              "hsa-miR-362-5p:PRKCA", "hsa-miR-193a-3p:TESK2", "hsa-miR-590-5p:TESK2", 
                                                                              "hsa-miR-331-3p:THBS1"), class = "data.frame") %>% 
mutate(UniquemRNA = as.numeric(mRNA))
#>       avecor             miR  mRNA UniquemRNA
#> 1 -0.9291998     hsa-miR-630 IGF1R          1
#> 2 -0.7292285  hsa-miR-362-3p PRKCA          2
#> 3 -0.4319836  hsa-miR-362-5p PRKCA          2
#> 4 -0.5508884 hsa-miR-193a-3p TESK2          3
#> 5 -0.9784224  hsa-miR-590-5p TESK2          3
#> 6 -0.6278561  hsa-miR-331-3p THBS1          4

Answer 2

I use R base package.

 df<-structure(list(avecor = c(-0.929199786400515, -0.729228501795928, 
    -0.431983639087243, -0.55088842103792, -0.978422379116014, -0.627856061946295
    ), miR = structure(c(9L, 5L, 6L, 2L, 8L, 4L), .Label = c("hsa-miR-107", 
    "hsa-miR-193a-3p", "hsa-miR-28-5p", "hsa-miR-331-3p", "hsa-miR-362-3p", 
    "hsa-miR-362-5p", "hsa-miR-429", "hsa-miR-590-5p", "hsa-miR-630"
    ), class = "factor"), mRNA = structure(c(1L, 2L, 2L, 3L, 3L, 
    4L), .Label = c("IGF1R", "PRKCA", "TESK2", "THBS1", "TLN2", "VAV3"
    ), class = "factor")), row.names = c("hsa-miR-630:IGF1R", "hsa-miR-362-3p:PRKCA", 
    "hsa-miR-362-5p:PRKCA", "hsa-miR-193a-3p:TESK2", "hsa-miR-590-5p:TESK2", 
    "hsa-miR-331-3p:THBS1"), class = "data.frame")



 UniquemRNA<-c()
    for (i in 1:length(table(df$mRNA))){
      fre <- rep(i, table(df$mRNA)[[i]])
        UniquemRNA<-c(UniquemRNA,fre)
    }
    UniquemRNA
df$UniquemRNA<-UniquemRNA
df