Matrix inversion is usually a costly computation and there may be some benefit to caching the inverse of a matrix rather than computing it repeatedly.
This is an example code to cache an inverse of a matrix which then called if:
- The new matrix computation similar to the previous matrix
- Matrix is invertible — Read Invertible Matrix
- The structure and content of the new matrix is equal to previous The program consists of two functions
A function to cache the matrix and the inverse. It is similar to getter and setter in many programming languages like Java and C.
A function which will be call for the computational process of the matrix
Here are parts of the code:
Setting the matrix
invMatrix <- NULL
#define the set function for the matrix
set <- function(y) {
x <<- y
invMatrix <<- NULL
}
Setting the inverse matrix
setInvMatrix <- function(invM){
invMatrix <<- invM ##assign the inverse matrix to the environment var
}
##define the function for returning the inverse matrix
getInvMatrix <- function(){
invMatrix ##the environment var inverse matrix is return
}
Verification on the matrix
if (!is.null(invM)){
## check if the return invMatrix is identical
if ( identical( x$get() %*% invM, invM %*% x$get() ) ){
## get it from the cache and skips the computation.
print("getting cached data")
return(invM)
}
}
Setting the new inverse
data <- x$get()
invM <- solve(data, ...)
# sets the value of the inverse in the cache via the setinv function.
x$setInvMatrix(invM)
Complete source code is reachable at https://github.com/masteramuk/ProgrammingAssignment2
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