log itとは 意味・読み方・使い方

語源

Blend of logistic +‎ unit, by analogy with probit, coined by American statistician Joseph Berkson in 1944: “I use this term [logit] for ${\displaystyle \ln p/q}$ following Bliss, who called the analogous function which is linear on ${\displaystyle x}$ for the normal curve ‘probit.’”

発音

• (米国発音) IPA: /ˈloʊd͡ʒɪt/, /ˈlɑd͡ʒɪt/
• (英国発音) IPA: /ˈlɒd͡ʒɪt/

名詞

logit (plural logits)

1. (mathematics) The inverse of the sigmoid or logistic function used in mathematics, especially in statistics. The logit of a number p between 0 and 1 is given by the formula:

   ${\displaystyle \operatorname {logit} (p)=\log \left({\frac {p}{1-p}}\right)=\log(p)-\log(1-p).\!\,}$

   • 2002, chapter 3, in Behavioral Models‎, UC Berkeley, archived from the original on 26 April 2022, page 38:

     The relation of the logit formula to the distribution of unobserved utility (as opposed to the characteristics of choice probabilities) was developed by Marley, as cited by Luce and Suppes (1965), who showed that the extreme value distribution leads to the logit formula.

   • 2002, chapter 6, in Behavioral Models‎, UC Berkeley, archived from the original on 26 April 2024, page 138:

     Improvements in computer speed and in our understanding of simulation methods have allowed the full power of mixed logits to be utilized.

2. (finance, metonymic, informal) A logistic regression, which applies such a mathematical function.

関連する語

• probit

参考

• bit

参照