I have an 8 by 3 matrix like this:
A B C
1 1 1 1
2 1 1 2
3 1 2 1
4 1 2 2
5 2 1 1
6 2 1 2
7 2 2 1
8 2 2 2
I want to create a column vector from this matrix like this:
cell
111
112
121
122
211
212
221
222
This means converting all the 3 columns into a single column. How can I do this? what are the codes?
We can use paste
data.frame(cell = as.integer(do.call(paste0, df1)))
-output
# cell
#1 111
#2 112
#3 121
#4 122
#5 211
#6 212
#7 221
#8 222
NOTE: In the reproducible example, we used data.frame as input. If it is a matrix, convert to data.frame with as.data.frame and apply the same code
Or use unite
library(tidyr)
library(dplyr)
unite(df1, cell, everything(), sep="") %>%
type.convert(as.is = TRUE)
df1 <- structure(list(A = c(1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L), B = c(1L,
1L, 2L, 2L, 1L, 1L, 2L, 2L), C = c(1L, 2L, 1L, 2L, 1L, 2L, 1L,
2L)), class = "data.frame", row.names = c("1", "2", "3", "4",
"5", "6", "7", "8"))
Use matrix multiplication as follows:
m %*% 10^(2:0)
giving:
[,1]
1 111
2 112
3 121
4 122
5 211
6 212
7 221
8 222
m in reproducible form:
Lines <- "
A B C
1 1 1 1
2 1 1 2
3 1 2 1
4 1 2 2
5 2 1 1
6 2 1 2
7 2 2 1
8 2 2 2"
m <- as.matrix(read.table(text = Lines))
