Question

我收到此错误：

Error in x$getinverse : $ operator is invalid for atomic vectors

我的代码是这样的。我不明白我在哪里弄错了。

##create a function which starts with a null matrix argument
makeCacheMatrix <- function(x = matrix()) { 
  ## initialize the value of the matrix inverse to NULL
  matrixinverse <- NULL                     
  ## delcare another function set where the value will be cached in 1. Matrix is created
  ## for the first time. 2. changes made to cached matrix
  set <- function(y) {                      
    x <<- y
    ## change the value of inverse of the matrix in case the matrix was changed.
    matrixinverse <<- NULL              
  }
  ## gets the value of the inverse
  get <- function() x                           
  #calculates the inverse of non-singular matrix via the solve function
  setinverse <- function(solve) matrixinverse <<- solve 
  # gets the inverse     
  getinverse <- function() matrixinverse        
  ## passes the value of the function makeCacheMatrix        
  list(set = set, get = get,                    
       setinverse = setinverse,
       getinverse = getinverse)
}

# used to get the cache of the matrix
cacheSolve<- function(x, ...) {                 
  matrixinverse <- x$getinverse()
  #if the inverse exists, it gets it.
  if(!is.null(matrixinverse)) {                 
    message("getting cached data - Inverse of the matrix")
    return(matrixinverse)
  }
  #if the inverse if not there, first it is calculated and then retrieved.
  data <- x$get()                               
  matrixinverse <- solve(data, ...)
  x$setinverse(matrixinverse)
  matrixinverse
}

Answer 1

You probably are passing the matrix itself to the cacheSolve function , rather than passing the return object of the makeCacheMatrix. 
I was facing the same problem earlier. I corrected the input parameter for cacheSolve and it worked.

Here is the illustration :
> mat<-matrix(c(1,4,9,0,-3,2,2,7,8),3,3)
> mat
     [,1] [,2] [,3]
[1,]    1    0    2
[2,]    4   -3    7
[3,]    9    2    8

m1<-makeCacheMatrix(mat)
> cacheSolve(mat)
Error in x$getinverse : $ operator is invalid for atomic vectors

But if you correct the input and re-run :
> cacheSolve(m1)
         [,1]    [,2]     [,3]
[1,] -1.18750  0.1250  0.18750
[2,]  0.96875 -0.3125  0.03125
[3,]  1.09375 -0.0625 -0.09375


Hope that helps !

Answer 2

我发现更改函数以指定y也是一个矩阵解决了问题。希望这有帮助！

set <- function(y = matrix()) {                      
    x <<- y*
    ...
}

x $ getinverse中的错误：$运算符对原子向量无效

2 个答案: