What is the exact algorithm used in nlm function in R. The documentation says:
This function carries out a minimization of the function f using a Newton-type algorithm. See the references for details.
Then in references:
Dennis, J. E. and Schnabel, R. B. (1983) Numerical Methods for Unconstrained Optimization and Nonlinear Equations. Prentice-Hall, Englewood Cliffs, NJ.
Schnabel, R. B., Koontz, J. E. and Weiss, B. E. (1985) A modular system of algorithms for unconstrained minimization. ACM Trans. Math. Software, 11, 419–440.
Out of these references, first one is a book and I do not know where to look at in the book. Second is a 42 page paper which describes a system of algorithms as implemented in FORTRAN package
UNCMIN. I did not read it, but then I am not sure if reading it completely will give answer to my question. (given that I don't know anything about FORTRAN it seems harder to start with).
Then as per the documentation
The current code is by Saikat DebRoy and the R Core team, using a C translation of Fortran code by Richard H. Jones.
nlm is translated, and not directly built using algorithm. So is there any algorithm/pseudo code for the Fortran code by Richard H.