For the Coursera course R Programming
The following code demonstrates how to use the assessment3.R R script.
Lines starting with # are simple comments, lines starting with #> are things
printed in the output.
# read the R script
# replace the "path/to/file" with the directory you save the file into
# or you can read the file directly from the web
source("path/to/file/assessment3.R")
# create a *square* matrix (because `solve` only handles square matrices)
# create the matrix during the call of makeCacheMatrix()
a <- makeCacheMatrix( matrix(c(1,2,12,13), nrow = 2, ncol = 2) );
summary(a);
#> Length Class Mode
#> setMatrix 1 -none- function
#> getMatrix 1 -none- function
#> cacheInverse 1 -none- function
#> getInverse 1 -none- function
a$getMatrix();
#> [,1] [,2]
#> [1,] 1 12
#> [2,] 2 13
cacheSolve(a)
#> [,1] [,2]
#> [1,] -1.1818182 1.09090909
#> [2,] 0.1818182 -0.09090909
# the 2nd time we run the function,we get the cached value
cacheSolve(a)
#> getting cached data
#> [,1] [,2]
#> [1,] -1.1818182 1.09090909
#> [2,] 0.1818182 -0.09090909
Alternatively, the matrix can be created after calling a makeCacheMatrix
without arguments.
# read the R script
# replace the "path/to/file" with the directory you save the file into
# or you can read the file directly from the web
source("path/to/file/assessment3.R")
# call makeCacheMatrix without arguments
a <- makeCacheMatrix();
summary(a);
#> Length Class Mode
#> setMatrix 1 -none- function
#> getMatrix 1 -none- function
#> cacheInverse 1 -none- function
#> getInverse 1 -none- function
# create a square matrix (reason `solve` only handles square matrices )
a$setMatrix( matrix(c(1,2,12,13), nrow = 2, ncol = 2) );
a$getMatrix();
#> [,1] [,2]
#> [1,] 1 12
#> [2,] 2 13
cacheSolve(a)
#> [,1] [,2]
#> [1,] -1.1818182 1.09090909
#> [2,] 0.1818182 -0.09090909
# the 2nd time we run the function, we get the cached value
cacheSolve(a)
#> getting cached data
#> [,1] [,2]
#> [1,] -1.1818182 1.09090909
#> [2,] 0.1818182 -0.09090909