Programming Assignement2

.Rhistory

@@ -0,0 +1,13 @@
+setwd("C:/Users/Chandru/ProgrammingAssignment2")
+source("cachematrix.R"")
+""
+source("cachematrix.R")
+mat <- matrix(rnorm(1:(16)), nrow=4, ncol=4)
+a <- makeCacheMatrix(mat)
+cacheSolve(a)
+cacheSolve(a)
+source("cachematrix.R")
+mat <- matrix(rnorm(1:(16)), nrow=4, ncol=4)
+a <- makeCacheMatrix(mat)
+cacheSolve(a)
+cacheSolve(a)

cachematrix.R

@@ -1,15 +1,43 @@
-## Put comments here that give an overall description of what your
-## functions do
+## The following functions speed up to compute repeated matrix inversion 
+## for a single matrix using caching technique 
 
-## Write a short comment describing this function
+
+## This function creates a special "matrix" object that can cache its inverse.
 
 makeCacheMatrix <- function(x = matrix()) {
+            im <- NULL                                      ## im for inversion matrix
+
+            set <- function(y) {                            ## set the matrix 
+                  x <<- y
+                  im <<- NULL
+            }
+            get <- function() x                             ## get the matrix
+            setinv <- function(solve) im <<- solve          ## set inversion matrix
+            getinv <- function() im                         ## get inversion matrix
+
+            list(set = set,                                 ## store the functions
+                 get = get,
+                 setinv = setinv,
+                 getinv = getinv)
 
 }
 
 
-## Write a short comment describing this function
+## 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, ...) {
         ## Return a matrix that is the inverse of 'x'
+
+        im <- x$getinv()                                     ## get inversion from cache
+
+        if(!is.null(im)){                                    ## check if it is not NULL
+                  message("getting cached data")
+                  return(im)                                 ## return the cache data and save some computation   
+        } 
+        data <- x$get()                                      ## if we are here we need compute
+        im <- solve(data, ...)                               ## compute the inverse
+        x$setinv(im)                                         ## save it to cache
+        im                                                   ## return the computed inverse matrix
 }