How to use dcast() to convert a 5x2 data.table to a 1x5 data.tabe?

Question

I have the following data.table

DT

ABBREVIATION    FULL_TEXT
-----------------------------
    DCD         TEXT1
    PCK         TEXT2
    KLM         TEXT3
    NOP         TEXT4
    XYZ         TEXT5

I would like to transform the data.table such that each "ABBREVIATION" is it's own column name. And there's one row that details the "FULL_TEXT", so

DCD     PCK     KLM     NOP     XYZ
------------------------------------
TEXT1   TEXT2   TEXT3   TEXT4   TEXT5

I tried using

dcast(DT, FULL_TEXT ~ ABBREVIATION, value.var = "FULL_TEXT")

but that doesn't work. Thanks

Answer 1

dcast(df, 1 ~ ABBREVIATION, value.var = 'FULL_TEXT')[, -1, with = FALSE]
#      DCD   KLM   NOP   PCK   XYZ
# 1: TEXT1 TEXT3 TEXT4 TEXT2 TEXT5

You should use transpose instead though

data.table::transpose(df, make.names = 'ABBREVIATION')
#      DCD   PCK   KLM   NOP   XYZ
# 1: TEXT1 TEXT2 TEXT3 TEXT4 TEXT5

Data used

df <- fread('
ABBREVIATION    FULL_TEXT
    DCD         TEXT1
    PCK         TEXT2
    KLM         TEXT3
    NOP         TEXT4
    XYZ         TEXT5
')