Function
NumCosmoMathutil_lambert_W0_ln
Declaration [src]
gdouble
ncm_util_lambert_W0_ln (
const gdouble ln_y
)
Description [src]
Computes the principal branch $W_0(y)$ of the Lambert $W$ function from $\ln y$, so that $y$ may exceed the double range. Uses gsl_sf_lambert_W0() for $\ln y < \ln(\mathrm{DBL_MAX}) - 1$, otherwise Newton’s method on $W + \ln W = \ln y$. Aborts if Newton’s method does not converge.