Question

如何在R？

中将矩阵列表写入csv文件

我试过

fff = tr[[3]]  
 MATweight = ldply(fff, function(t) t$toDataFrame())

但有这个错误

Error in t$toDataFrame : $ operator is invalid for atomic vectors

我不确定这是否是正确的做法，请问任何想法？

我有这个矩阵列表

    > str(fff)
    List of 10
     $ : num [1:1000, 1:50] 1 1 1 1 2 2 1 2 2 1 ...
....
     $ : num [1:1000, 1:50] 1 1 1 1 2 2 1 2 2 1 ..

当我尝试G的建议答案时，我得到了：

 > write.csv(map_dfr(fff, as.data.frame, .id = "matrix"),"testt.csv",  row.names = FALSE)
    > tgtg = read.csv("/Users/amani/testt.csv")
    > str(tgtg)
    'data.frame':   10000 obs. of  51 variables:
     $ matrix: int  1 1 1 1 1 1 1 1 1 1 ...
     $ V1    : int  1 1 1 1 2 2 1 2 2 1 ...
     $ V2    : int  2 2 1 2 1 1 2 1 1 2 ...
     $ V3    : int  1 1 1 1 1 2 1 1 2 1 ...
....
     $ V50   : int  2 2 1 1 1 1 1 1 2 2 ...

Answer 1

使用显示的L测试数据，从purrr：

尝试map_dfr

library(purrr)

L <- list(as.matrix(BOD), as.matrix(10*BOD)) # test data

write.csv(map_dfr(L, as.data.frame, .id = "matrix"), stdout(), row.names = FALSE)

，并提供：

"matrix","Time","demand"
"1",1,8.3
"1",2,10.3
"1",3,19
"1",4,16
"1",5,15.6
"1",7,19.8
"2",10,83
"2",20,103
"2",30,190
"2",40,160
"2",50,156
"2",70,198

Answer 2

为什么不这样做：

# sample data like your `fff` list of matrices
fff <- lapply(1:10, function(i) 
  matrix(data = sample(1:2, 510000, replace = TRUE), nrow = 10000, ncol = 51))


# we give each matrix in the list a unique name
mat_names <- as.character(1:length(fff))

# converting to dataframe with the list index preserved
fffdf <- lapply(1:length(fff), function(i)
  cbind(mat_names = mat_names[i], as.data.frame(fff[[i]])))
fffdf <- do.call(rbind, fffdf)

# writing it to a file
t <- tempfile(fileext = ".csv")
write.csv(fffdf, t, row.names = FALSE)

# testing the reassembly into the same list of matrices that you started
tcsv <- read.csv(t)
tgtg <- lapply(mat_names, function(i) {
  df <- subset(tcsv, mat_names == i, select = -mat_names)
  mat <- as.matrix(df)
  dimnames(mat) <- NULL
  return(mat)
})

测试结果：tgtg与您开始的fff相同吗？

> identical(fff, tgtg)
[1] TRUE

> str(tgtg)
List of 10
 $ : int [1:10000, 1:51] 1 2 1 2 1 1 2 2 1 1 ...
 $ : int [1:10000, 1:51] 2 2 2 2 2 2 1 1 1 1 ...
 $ : int [1:10000, 1:51] 1 2 1 1 2 2 1 1 2 1 ...
 $ : int [1:10000, 1:51] 1 1 2 2 1 1 1 2 1 1 ...
 $ : int [1:10000, 1:51] 1 1 2 1 2 2 1 1 1 2 ...
 $ : int [1:10000, 1:51] 2 1 2 2 1 1 1 2 1 2 ...
 $ : int [1:10000, 1:51] 2 1 2 1 2 1 1 1 2 1 ...
 $ : int [1:10000, 1:51] 2 2 1 1 2 2 1 2 1 1 ...
 $ : int [1:10000, 1:51] 1 2 1 1 1 1 1 2 2 1 ...
 $ : int [1:10000, 1:51] 1 1 1 2 2 2 2 2 2 2 ...

写一个矩阵列表到csv？

2 个答案: