1- # # Put comments here that give an overall description of what your
2- # # functions do
1+ # # This program calculates the inverse of a Matrix. For efficiency' sake, it also leverages
2+ # # a cache memory in order to avoid recalculating an inverse matrix previously done.
3+ # #
4+ # # Usage:
5+ # # 1. Assign the makeCacheMatrix' returned Matrix to a variable
6+ # # 2. Calculate its inverse Matrix using cacheSolve
7+ # # 3. Call cacheSolve one more time to verify it is using a cache
8+ # # 4. Clear cache redoing step 1 and repeat step 2 to check the cache is not used
9+ # #
10+ # # Example:
11+ # # 1. matrixTest = makeCacheMatrix( matrix( c(2,0,1,3,0,0,5,1,1), nrow=3, ncol=3, byrow=TRUE ) )
12+ # # 2. cacheSolve( matrixTest )
13+ # # 3. cacheSolve( matrixTest )
14+ # # 4. matrixTest = makeCacheMatrix( matrix( c(2,0,1,3,0,0,5,1,1), nrow=3, ncol=3, byrow=TRUE ) )
15+ # # cacheSolve( matrixTest )
16+ # #
317
4- # # Write a short comment describing this function
18+ # # makeCacheMatrix sets up an special Matrix object, which contains 2 variables
19+ # # getters and setters functions for each one of them.
20+ # # By default, the Matrix is initialized empty. Another matrix can be passed as parameter.
21+ # # The inverse of a Matrix can only be calculated for a squared matrix, which means it has to have the same number of rows and columns.
22+ # #
523
624makeCacheMatrix <- function ( dataMatrix = matrix () ) {
725 inverseMatrix <- NULL
826
27+ # # Set the matrix
928 set <- function ( newDataMatrix ) {
10- dataMatrix <<- newDataMatrix
29+ dataMatrix <<- newDataMatrix
1130 inverseMatrix <<- NULL
1231 }
1332
33+ # # Get the matrix
1434 get <- function () dataMatrix
1535
36+ # # Set the inverse of the matrix
1637 setInverse <- function ( inverse ) inverseMatrix <<- inverse
1738
39+ # # Get the inverse of the matrix
1840 getInverse <- function () inverseMatrix
1941
20- list (set = set , get = get ,
42+ # # Return a list with all setter and getter functions
43+ list (set = set ,
44+ get = get ,
2145 setInverse = setInverse ,
2246 getInverse = getInverse )
2347}
2448
2549
26- # # Write a short comment describing this function
50+ # # cacheSolve returns the inverse of a makeCacheMatrix object passed as parameter.
51+ # # In case the inverse is stored in a cache, it returns the value stored there,
52+ # # otherwise the inverse is calculated.
53+ # #
2754
28- cacheSolve <- function (x , ... ) {
29- # # Return a matrix that is the inverse of 'x'
30- inverse <- x $ getInverse()
55+ cacheSolve <- function ( matrix , ... ) {
56+ # # Verify the inverse matrix is cached
57+ inverse <- matrix $ getInverse()
58+
3159 if ( ! is.null( inverse ) ) {
3260 message( " Getting cached data..."
3361 return ( inverse )
3462 }
35- data <- x $ get()
63+
64+ # # In case it is not cached, calculate it
65+ data <- matrix $ get()
3666 inverse <- solve( data , ... )
37- x $ setInverse( inverse )
67+ matrix $ setInverse( inverse )
68+
3869 inverse
39- }
70+ }
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