「as.X」運算符通常將一種類型轉換爲另一種類型,但as.integer在應用於數組時失敗。這是一個錯誤?這是Microsoft R Open 3.3的64位版本,也是R Foundation的R 3.3.1 for i686-pc-cygwin(32位)。R:爲什麼as.character將int matrix轉換爲char,但是as.integer不會將char matrix轉換爲int?
> m <- matrix(rnorm(25), 5)
> m
[,1] [,2] [,3] [,4] [,5]
[1,] -0.5958330 -0.3139274 -0.4746246 0.2431716 -0.5245235
[2,] 0.5677058 0.1944457 -2.3786936 0.2516587 -0.3541963
[3,] 0.6763564 -1.7285476 -0.5878008 -1.2277048 0.7737145
[4,] -1.4607755 -0.4761012 1.0995414 0.6978072 0.6120277
[5,] 0.8593707 0.2962030 1.1791963 -0.2276658 1.1559314
> m[] <- as.integer(m)
> m
[,1] [,2] [,3] [,4] [,5]
[1,] 0 0 0 0 0
[2,] 0 0 -2 0 0
[3,] 0 -1 0 -1 0
[4,] -1 0 1 0 0
[5,] 0 0 1 0 1
> m[] <- as.character(m)
> m
[,1] [,2] [,3] [,4] [,5]
[1,] "0" "0" "0" "0" "0"
[2,] "0" "0" "-2" "0" "0"
[3,] "0" "-1" "0" "-1" "0"
[4,] "-1" "0" "1" "0" "0"
[5,] "0" "0" "1" "0" "1"
> m[] <- as.integer(m)
> m
[,1] [,2] [,3] [,4] [,5]
[1,] "0" "0" "0" "0" "0"
[2,] "0" "0" "-2" "0" "0"
[3,] "0" "-1" "0" "-1" "0"
[4,] "-1" "0" "1" "0" "0"
[5,] "0" "0" "1" "0" "1"
如果您分配給矩陣或向量的子集,矩陣/向量的類型只能更改爲更高(更一般)的類型。 – Roland
......特別是,'m [] < - as.integer(m)'按我的想法工作,我想。 – joran
@joran:m [] < - as.integer(m)不能像我期望的那樣工作。查看我已發佈的代碼。 –