R inverting matrix with error return error
I am learning R programming.
I am trying to invert a matrix. Below I have tried.
x <- matrix(1:16, 4, 4)
x
# [,1] [,2] [,3] [,4]
# [1,] 1 5 9 13
# [2,] 2 6 10 14
# [3,] 3 7 11 15
# [4,] 4 8 12 16
solve(x)
# Error in solve.default(x) :
# Lapack routine dgesv: system is exactly singular: U[3,3] = 0
solve(x) %*% x
# Error in solve.default(x) :
# Lapack routine dgesv: system is exactly singular: U[3,3] = 0
x %*% solve(x)
# Error in solve.default(x) :
# Lapack routine dgesv: system is exactly singular: U[3,3] = 0
I can't figure out what "only" means. According to this it says that if it solve
doesn't have a second parameter, it will invert the first parameter.
I am totally confused so need some explanation with an example would be great.
If you are calculating determinant
matrices it is 0
:
det(x)
[1] 0
By definition, your matrix is not reversible. But before attempting to invert a square matrix, the first instinct should be to investigate analytically if the matrix can be invertible.
The only error you get is simply reflecting the matrix, not reversible.