tiny_R_script.R

tiny_R_script.R

x  <- c(100,100,100,200,200,300,300,300,400)
y  <- rep( c('A','B','C'), 3 )
z  <- sample(1:9,9, replace = T)
df <- data.frame(x,y,z)

library(Matrix)

x1 <- factor(df$x)
y1 <- factor(df$y)




sparseMatrix(
    i = as.integer(x1)
  , j =  as.integer(y1)
  , x = df$z
  , dims = c(length(levels(x1)), length(levels(y1)) )
  , dimnames = list(levels(x1),levels(y1))
) -> sm1

df %>% pivot_wider(names_from = x, values_from = z) -> sm2
str(sm1)
str(sm2)