R：重命名矩阵的列/行的省时方法

Question

Is there a more efficient way of doing this: The matrix expr is 15745 x 41

for (i in 1:ncol(expr)){
   colnames(expr)[i] <- paste0("V",i);
}
for (i in 1:nrow(expr)){
   rownames(expr)[i] <- paste0(i);
}

Answer 1

colnames(expr) <- paste0("V",1:ncol(expr))
rownames(expr) <- 1:nrow(expr)

Answer 2

We can use dimnames to do this

dimnames(expr) <- list(seq_len(nrow(expr)), paste0("V", seq_len(ncol(expr))))

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Or this can be also done with explicitly assigning colnames and rownames as we have commented earlier

colnames(expr) <- paste0("V", seq_len(ncol(expr)))
rownames(expr) <- seq_len(nrow(expr))

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Or another option is to convert it to data.frame which will automatically do the naming (if working with data.frame is okay)

as.data.frame(expr)

data

set.seed(24)
expr <- matrix(rnorm(10*5), 10, 5)