fill functions with code

Author: peter-cmw

cachematrix.R

@@ -2,14 +2,40 @@
 ## functions do
 
 ## Write a short comment describing this function
-
+## makeCacheMatrix constructs an object for caching matrix inverse
+## it has methods for getting and setting source matrix and cached inverse value  
 makeCacheMatrix <- function(x = matrix()) {
-
+    inv <- NULL
+    set <- function(y) {
+        x <<- y
+        inv <<- NULL
+    }
+    get <- function() x
+    setinv <- function(inverse) inv <<- inverse
+    getinv <- function() inv
+    list(set = set, get = get,
+         setinv = setinv,
+         getinv = getinv)
 }
 
 
 ## Write a short comment describing this function
-
+## cacheSolve is a function that gets matrix inverse from cache if already solved 
+## and if not it solves inverse and stores value to cache 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    ##check for matrix to be square
+    data <- x$get()
+    if (nrow(data) != ncol(data)){
+        message("Error: Matrix should be square")
+    }
+    
+    ## Return a matrix that is the inverse of 'x'
+    inv <- x$getinv()
+    if(!is.null(inv)) {
+        message("getting cached data")
+        return(inv)
+    }
+    inv <- solve(data, ...)
+    x$setinv(inv)
+    inv
 }