Ratio between Pr and Ptot (photoequilibrium) for Type I Phytochrome.
Pfr_P_ratio_mono(w.length)a single value or a vector of numeric values giving the unitless ratio
a single value or a vector of wavelengths (nm)
Exact only for narrow band light sources!
Mancinelli, A.L. (1994) The physiology of phytochrome action. In Photomorphogenesis in plants, 2nd edition. R.E. Kendrick and G.H.M. Kronenberg, eds. Kluwer Academic Publishers, Dordrecht, pp. 211-269. ISBN 978-0-7923-2551-2 (print), 978-94-011-1884-2 (on-line). tools:::Rd_expr_doi("10.1007/978-94-011-1884-2_10")