Inverse of matrix in R

user_156458 0
Viewed 267580

I was wondering what is your recommended way to compute the inverse of a matrix?

The ways I found seem not satisfactory. For example, 

> c=rbind(c(1, -1/4), c(-1/4, 1))  
> c  
      [,1]  [,2]  
[1,]  1.00 -0.25  
[2,] -0.25  1.00  
> inv(c)  
Error: could not find function "inv"  
> solve(c)    
          [,1]      [,2]  
[1,] 1.0666667 0.2666667  
[2,] 0.2666667 1.0666667  
> solve(c)*c  
            [,1]        [,2]  
[1,]  1.06666667 -0.06666667  
[2,] -0.06666667  1.06666667  
> qr.solve(c)*c  
            [,1]        [,2]  
[1,]  1.06666667 -0.06666667  
[2,] -0.06666667  1.06666667

Thanks!

matrix-inverse r
5 Answers

solve(matrix) = Inverse of the matrix, it does the job perfectly.

user_181293740

Use solve(matrix) if the matrix is larger than 1820x1820. Using inv() from matlib or ginv() from MASS takes longer or will not solve at all because of RAM limits.

user_184883110
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