Converting from a list to numeric in R

Question

I recently had a problem in which everytime I read a csv file containing a table with values, R read it as a list format instead of numeric. As no thread provided me the entire

Answer 1

Here is a shorter/faster way to turn your data.frame into a numeric matrix:

data <- data.matrix(data)

There is also

data <- as.matrix(data)

but one important difference is if your data contains a factor or character column: as.matrix will coerce everything into a character matrix while data.matrix will always return a numeric or integer matrix.

data <- data.frame(
  logical   = as.logical(c(TRUE, FALSE)),
  integer   = as.integer(c(TRUE, FALSE)),
  numeric   = as.numeric(c(TRUE, FALSE)),
  factor    = as.character(c(TRUE, FALSE))
)

data.matrix(data)
#      logical integer numeric factor
# [1,]       1       1       1      2
# [2,]       0       0       0      1

as.matrix(data)
#      logical integer numeric factor 
# [1,] " TRUE" "1"     "1"     "TRUE" 
# [2,] "FALSE" "0"     "0"     "FALSE"