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rpivotreshapetidyrreshape2

Transforming data from wide to long where 'lengths(varying)' > 'length(times)'


I am trying to convert data from df to df2.

> df
  part.id bl.rbc bl.serum bl.hp bl.epfa sm.rbc sm.serum sm.hp sm.epfa oy.rbc oy.serum oy.hp
1       1     NA       NA    NA      NA     NA       NA    NA      NA     NA       NA    NA
2       2     NA       NA    NA      NA     NA       NA    NA      NA     NA       NA    NA
3       3     NA       NA    NA      NA     NA       NA    NA      NA     NA       NA    NA
  oy.epfa
1      NA
2      NA
3      NA


> df2
  part.id timepoint rbc serum hp epfa
1       1        bl  NA    NA NA   NA
2       2        sm  NA    NA NA   NA
3       3        oy  NA    NA NA   NA

I tried reshape but I get an error if lengths(varying) = 4 > length(time) = 3. My actual case involves 16 varying.

Code to create these:

part.id <- c(1,2,3)
bl.rbc <- NA
bl.serum <- NA
bl.hp <- NA
bl.epfa <- NA
sm.rbc <- NA
sm.serum <- NA
sm.hp <- NA
sm.epfa <- NA
oy.rbc <- NA
oy.serum <- NA
oy.hp <- NA
oy.epfa <- NA


df <- data.frame(part.id, 
                 bl.rbc, bl.serum, bl.hp, bl.epfa, 
                 sm.rbc, sm.serum, sm.hp, sm.epfa,
                 oy.rbc, oy.serum, oy.hp, oy.epfa)

timepoint <- c("bl", "sm", "oy")

rbc <- NA
serum <- NA
hp <- NA
epfa <- NA

df2 <- data.frame(part.id, timepoint, rbc, serum, hp, epfa)

Solution

  • This doesn't match your expected output, but perhaps what you intended?

    library(tidyverse)
    library(stringr)
    
    df %>%
      rename_at(-1, ~ str_replace(., "(\\w+).(\\w+)", "\\2_\\1")) %>% 
      pivot_longer(-part.id, names_to = c(".value", "timepoint"), names_sep='_')
    
    # A tibble: 9 x 6
      part.id timepoint rbc   serum hp    epfa 
        <dbl> <chr>     <lgl> <lgl> <lgl> <lgl>
    1       1 bl        NA    NA    NA    NA   
    2       1 sm        NA    NA    NA    NA   
    3       1 oy        NA    NA    NA    NA   
    4       2 bl        NA    NA    NA    NA   
    5       2 sm        NA    NA    NA    NA   
    6       2 oy        NA    NA    NA    NA   
    7       3 bl        NA    NA    NA    NA   
    8       3 sm        NA    NA    NA    NA   
    9       3 oy        NA    NA    NA    NA