tridiag RRR routines

Collaboration diagram for tridiag RRR routines:

Topics
	larra: step in stemr
	larrb: step in stemr
	larrc: step in stemr
	larrd: step in stemr, tridiag eig
	larre: step in stemr
	larrf: step in stemr, find relative robust representation (RRR)
	larrj: step in stemr, refine eigval estimates
	larrk: step in stemr, compute one eigval
	larrr: step in stemr, test to do expensive tridiag eig algorithm
	larrv: eig tridiagonal, step in stemr & stegr
	lar1v: step in larrv, hence stemr & stegr

Detailed Description