[R] matrix log

[Spencer Graves]

	  I'm not aware of any R implementation of a logarithm of a matrix. 
I've seen discussions on this list of the difficulties involved in 
computing functions of matrices, but I know of nothing.  (The 'nlme' 
package has 'pdLogChol', which may be related, but I think it's 
different.)

	  I wish you luck, and I hope you will find the time to package it for 
the rest of us.

	  Best Wishes,
	  Spencer Graves	

Brandon.J.Whitcher at gsk.com wrote:
> Dear R users,
> 
> Has anyone implemented a "matrix log" function in R similar to the 
> function logm() in Matlab?  I did a quick R site search and browsed the 
> contributed packages to no avail.
> 
> The octave function is far too simplistic and fails for the Matlab test 
> matrix.  Ideally, the code of Cheng, Higham, and Laub (2001) or something 
> similar could be utilized.  Just checking before I spend time porting 
> code.
> 
> cheers...
> 
> Brandon
> 
> Translational Medicine & Genetics
> GlaxoSmithKline
> 	[[alternative HTML version deleted]]
> 
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