diff --git a/cachematrix.R b/cachematrix.R index a50be65aa44..f485ca09ac8 100644 --- a/cachematrix.R +++ b/cachematrix.R @@ -1,15 +1,75 @@ -## Put comments here that give an overall description of what your -## functions do +#Our aim in this experiment is to write a pair of functions, namely, +#"makeCacheMatrix" and "cacheSolve" that cache the inverse of a matrix -## Write a short comment describing this function +#makeCacheMatrix is a function which creates a special "matrix" object that can +#cache its inverse for the input (which is an invertible square matrix) makeCacheMatrix <- function(x = matrix()) { - + inv <- NULL + set <- function(y) { + x <<- y + inv <<- NULL + } + get <- function() x + setinv <- function(inverse) inv <<- inverse + getinv <- function() inv + list(set = set, get = get, setinv = setinv, getinv = getinv) } -## Write a short comment describing this function +#cacheSolve is a function which computes the inverse of the special "matrix" +#returned by makeCacheMatrix above. If the inverse has already been calculated +#(and the matrix has not changed), then the cachesolve should retrieve the +#inverse from the cache cacheSolve <- function(x, ...) { - ## Return a matrix that is the inverse of 'x' + inv <- x$getinv() + if(!is.null(inv)) { + message("getting cached result") + return(inv) + } + data <- x$get() + inv <- solve(data, ...) + x$setinv(inv) + inv } + + +#Checking the Output- +my_matrix <- makeCacheMatrix(matrix(1:4, 2, 2)) +my_matrix$get() +# [,1] [,2] +# [1,] 1 3 +# [2,] 2 4 +my_matrix$getinv() +# NULL +cacheSolve(my_matrix) +# [,1] [,2] +# [1,] -2 1.5 +# [2,] 1 -0.5 +my_matrix$getinv() +# [,1] [,2] +# [1,] -2 1.5 +# [2,] 1 -0.5 + + +my_matrix$set(matrix(c(2, 2, 1, 4), 2, 2)) +my_matrix$get() +# [,1] [,2] +# [1,] 2 1 +# [2,] 2 4 +my_matrix$getinv() +# NULL +cacheSolve(my_matrix) +# [,1] [,2] +# [1,] 0.6666667 -0.1666667 +# [2,] -0.3333333 0.3333333 +cacheSolve(my_matrix) +# getting cached result +# [,1] [,2] +# [1,] 0.6666667 -0.1666667 +# [2,] -0.3333333 0.3333333 +my_matrix$getinv() +# [,1] [,2] +# [1,] 0.6666667 -0.1666667 +# [2,] -0.3333333 0.3333333 \ No newline at end of file