If you fill a matrix cell with a character, R will convert the entire matrix into character values…so be careful = )
time <- c(1:4)
numbers <- c(1:4)
characters <- c('a', 'b', 'c', 'd')
count <- 0
df_mat <- matrix(, ncol = 3, nrow = length(time))
for(i in 1:length(time)){
count <- count + 1
df_mat[count, 1] <- time[i]
df_mat[count, 2] <- numbers[i]
df_mat[count, 3] <- characters[i]
}
df_mat
[,1] [,2] [,3]
[1,] "1" "1" "a"
[2,] "2" "2" "b"
[3,] "3" "3" "c"
[4,] "4" "4" "d" Notice that all cells are now characters. Characters are a huge problem if you are calculating values to place into the cells. That is, I wouldn’t be able to run code like this in a loop:
df_mat[count - 1, 2] <- df_mat[count - 1, 3] * 0.5
Instead, use numbers for everything and then change them to characters later.
time <- c(1:4)
numbers <- c(1:4)
characters <- c(1, 2, 3, 4) # here is the change
count <- 0
df_mat <- matrix(, ncol = 3, nrow = length(time))
for(i in 1:length(time)){
count <- count + 1
df_mat[count, 1] <- time[i]
df_mat[count, 2] <- numbers[i]
df_mat[count, 3] <- characters[i]
}
df_mat
[,1] [,2] [,3]
[1,] 1 1 1
[2,] 2 2 2
[3,] 3 3 3
[4,] 4 4 4Bo\(^2\)m =)