如何从R中的子列表计算元素

我的代码如下：

x <- data.frame(matrix(rnorm(20), nrow=10))
colnames(x) <- c("z", "m")
n_boot<-4
bs <- list()

for (i in 1:n_boot) {
 bs[[i]] <- x[sample(nrow(x), 10, replace = TRUE), ]
}

bt<-matrix(unlist(bs), ncol = 2*n_boot, byrow = FALSE)
colnames(bt) <- rep(c("z","m"),times=n_boot)
M_to_boot <- bt[,seq(2,8,by=2)]

funct<-function(M_boot_max) {  
   od<-(1/((10*((10^((16-M_boot_max-25)/5))^3)/3)*((max(M_boot_max)-min(M_boot_max))/50)))
}
V_boot<-apply(M_to_boot,2,funct)

rows.combined <- nrow(M_to_boot) 
cols.combined <- ncol(M_to_boot) + ncol(V_boot)
matrix.combined <- matrix(NA, nrow=rows.combined, ncol=cols.combined)
matrix.combined[, seq(1, cols.combined, 2)] <- M_to_boot
matrix.combined[, seq(2, cols.combined, 2)] <- V_boot
colnames(matrix.combined) <- rep(c("M_boot","V_boot"),times=n_boot)

df<-as.data.frame(matrix.combined)
start0 <- seq(1, by = 2, length = ncol(df) / 2)
start <- lapply(start0, function(i, df) df[i:(i+1)], df = df)

tests<-lapply(start, function(xy) split(xy, cut(xy$M_boot,breaks=5)))

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x我不太清楚你想要什么。您想对
测试的每个列表和子列表应用一个函数，在本例中是sum<代码>f这正是我需要的！非常感谢你！