[R] Query on finding root

[Leonard Mada]

Dear R-Users,

Just out of curiosity:
Which of the 2 methods is the better one?

The results seem to differ slightly.


fun = function(u){((26104.50*u^0.03399381)/((1-u)^0.1074444)) - 28353.7}

uniroot(fun, c(0,1))
# 0.6048184

curve(fun(x), 0, 1)
abline(v=0.3952365, col="red")
abline(v=0.6048184, col="red")
abline(h=0, col="blue")



fun = function(u){ (0.03399381*log(u) - 0.1074444*log(1-u)) - 
log(28353.7/26104.50) }
fun = function(u){ (0.03399381*log(u) - 0.1074444*log1p(-u)) - 
log(28353.7/26104.50) }

uniroot(fun, c(0,1))
# 0.6047968

curve(fun(x), 0, 1)
abline(v=0.3952365, col="red")
abline(v=0.6047968, col="red")
abline(h=0, col="blue")

Sincerely,

Leonard