cachematrix.R

## Doing Matrix Inversion calculation could take time. 
## Caching the result of an inversion on a matrix will greatly
## improve the performance of the program is the inversion 
## is reused more than once.
##
## The following functions cache the result of applying solve()
## on a matrix. If m is matrix, solve(m) returns the inversion of m

##---------------------------------------------------------------------##

## Create a matrix with setters, getters and cached result for solve()
makeCacheMatrix <- function(x = matrix()) {
    sol <- NULL
    
    set <- function(y) {x <<- y ; sol <<- NULL}
    get <- function() x
    
    setSol <- function(newSol) sol <<- newSol
    getSol <- function() sol
    
    list(set = set, get = get, setSol = setSol, getSol = getSol)
}

##---------------------------------------------------------------------##

## Retrive and assign cached value according to the presence of the cache
cacheSolve <- function(x, ...) {
    if(is.null(x$getSol()))
        x$setSol( solve(x$get(), ...) )
    else 
        message("getting cached data")
    x$getSol()
}

##---------------------------------------------------------------------##
##---------------------------------------------------------------------##

## Uncomment the next 4 lines of code to test the above functions
## (Hightlight the lines then use  Ctrl-Shift-C to uncomment)

# m<-makeCacheMatrix(matrix(1:4,2,2))
# cacheSolve(m)         # This call tests solve(a)
# cacheSolve(m)         # This call tests caching
# m$set(matrix(c(1,2,3,6,5,4,9,7,8),3,3,byrow=T))
# cacheSolve(m,m$get()) # This call tests solve(b,b)