Unpivoting dataframe

Question

I have a data frame looking like this : data.frame name cond

CONDITION  CONT1 CONT2  CONT3 CONT4 
result      16.2  2.5   6.5   0.75
Test.ratio  0.23  0.15  2.5   3.5

What I want to do get is:

CONDITION Result test.ratio
CONT1      16.2  0.62 
CONT2      2.5   0.15
CONT3      6.5   2.5 
CONT4      0.75  3.5

I tried using the melt function but it didnt work.

Cond.long <- melt(cond, idvar = "condition"))

I'm new to R.

Using `tidyr` : `df %>% pivot_longer(cols = -CONDITION) %>% pivot_wider(names_from = CONDITION, values_from = value)` — Ronak Shah, Mar 12 '21 at 06:47

score 1 · Answer 1 · answered Mar 12 '21 at 06:56

1

base

df <- read.table(text = "CONDITION  CONT1 CONT2  CONT3 CONT4 
result      16.2  2.5   6.5   0.75
Test.ratio  0.23  0.15  2.5   3.5 ", header = T)
new <- t(df[, -1]) 
colnames(new) <- df[, 1]
new
#>       result Test.ratio
#> CONT1  16.20       0.23
#> CONT2   2.50       0.15
#> CONT3   6.50       2.50
#> CONT4   0.75       3.50

^{Created on 2021-03-12 by the reprex package (v1.0.0)}

answered Mar 12 '21 at 06:56

Yuriy Saraykin

8,390
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1

Similar approach: `t("rownames<-"(as.matrix(df[, -1]), df[[1]]))`. – A5C1D2H2I1M1N2O1R2T1 Mar 13 '21 at 04:11

score 0 · Answer 2 · answered Mar 12 '21 at 06:47

Does this work:

library(dplyr)
library(tidyr)
df %>% pivot_longer(cols = starts_with('CONT')) %>% 
    pivot_wider(names_from = CONDITION) %>% select('CONDITION' = name, 2,3)
# A tibble: 4 x 3
  CONDITION result Test.ratio
  <chr>      <dbl>      <dbl>
1 CONT1      16.2        0.23
2 CONT2       2.5        0.15
3 CONT3       6.5        2.5 
4 CONT4       0.75       3.5

score 0 · Answer 3 · answered Mar 12 '21 at 08:52

Here is a data.table option using dcase + melt

> dcast(melt(setDT(df), id.vars = "CONDITION"), variable ~ CONDITION)
   variable Test.ratio result
1:    CONT1       0.23  16.20
2:    CONT2       0.15   2.50
3:    CONT3       2.50   6.50
4:    CONT4       3.50   0.75

Unpivoting dataframe

3 Answers3