cachematrix

#R Programming Assignment 2

Matrix inversion is usually a costly computation and there may be some benefit to caching the inverse of a matrix rather than computing it repeatedly.

##The two functions below are a pair of functions that cache the inverse of a matrix.

makeCacheMatrix creates a special "matrix", which is really a matrix containing a function to

##1.set the value of the matrix ##2.get the value of the matrix ##3.set the value of the inverse of the matrix ##4.get the value of the inverse of the matrix

makeCacheMatrix <- function(x = matrix()) { inv <- NULL set <- function(y) { x <<- y inv <<- NULL } get <- function() x setinv <- function(solve) inv <<- solve getinv <- function() inv list(set = set, get = get, setinv = setinv, getinv = getinv)
} m<-matrix(c(-1,-2,1,1), 2:2) u<-makeCacheMatrix(m) as.list(environment(u$get)) u$getinv()

##This function 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, ...) { inv <- x$getinv() if(!is.null(inv)) { message("getting cached data") return(inv) } data <- x$get() inv <- solve(data, ...) x$setinv(inv) inv } cacheSolve(u)