Programming Assignment 2

Author: aendrs

cachematrix.R

@@ -1,15 +1,61 @@
-## Put comments here that give an overall description of what your
-## functions do
 
-## Write a short comment describing this function
 
-makeCacheMatrix <- function(x = matrix()) {
+## makeCacheMatrix starts savinf null default values for some variables.
+# Then a few functions are defined inside for saving the input matrix and inverse, 
+# and for  returning the input matrix and getting the cached values.
+
+
+makeCacheMatrix <- function(in_mat = matrix()) {
+
+	#Save initial default Null values
+		saved_inv<-NULL
+		saved_mat<-NULL
+		
+		#Function for saving Matrix and Inverse in cache
+		setinv<-function(y){
+					saved_mat <<- y
+					saved_inv <<- solve(y)	
+		}
+		
+		#self explanatory functions
+		get_input_matrix <- function() in_mat
+		
+		get_saved_matrix <-function() saved_mat
+
+		getinv <-function() saved_inv
+		
+		list(setinv = setinv, get_input_matrix = get_input_matrix,
+             get_saved_matrix=get_saved_matrix, getinv=getinv)
 
 }
 
 
-## Write a short comment describing this function
+## cacheSolve starts retrieving the input and cached matrix. 
+# It compares both of them and if they are the same it retrieves the cached
+# inverse. If they are dissimilar it means the matrix has changed so it calculates
+# the inverse and saves it in cache.
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+        
+		#retrieve input matrix and cached matrix
+		inputmat <- x$get_input_matrix()
+		savedmat <- x$get_saved_matrix()
+		
+		#retrieve cached inverse
+		inv<- x$getinv()
+		
+		
+		#compare cached and input matrix, copy inverse when appropriate
+		if(!is.null(inv) && identical(inputmat, savedmat)  ) {
+				message("The inverse of this matrix has been calculated. 
+				Let's get the damn thing:")
+		        return(inv)
+		}else{
+				message("The inverse of this matrix is not in cache. 
+				I'll calculate it explicitly and save it.")
+				
+				newinv<-x$setinv(inputmat)
+				newinv
+		}
+				
 }