基于r中的函数对每一行进行计算

Question

我想使用这段代码，我在这里找到：Generate N random integers that sum to M in R。我试图使每种产品的标准偏差都具有计算功能。

rand_vect <- function(N, M, sd, pos.only = TRUE) {
  vec <- rnorm(N, M/N, sd)
  if (abs(sum(vec)) < 0.01) vec <- vec + 1
  vec <- round(vec / sum(vec) * M)
  deviation <- M - sum(vec)
  for (. in seq_len(abs(deviation))) {
    vec[i] <- vec[i <- sample(N, 1)] + sign(deviation)
  }
  if (pos.only) while (any(vec < 0)) {
    negs <- vec < 0
    pos  <- vec > 0
    vec[negs][i] <- vec[negs][i <- sample(sum(negs), 1)] + 1
    vec[pos][i]  <- vec[pos ][i <- sample(sum(pos ), 1)] - 1
  }
  vec
}

df <- data.frame(Product = c("A", "B", "C"), 
                   Oct = c(33, 23, 12),
                   Nov = c(23, 26, 19),
                      SD = c(2, 10, 5))

#I tried to do it like this, but it doesn't work correct:
df_new <- as.data.frame(sapply(unlist(df[c(2,3)]), rand_vect, N = 7, df$SD))