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The logit ( ) function is the inverse of the sigmoidal "logistic" function or logistic transform used in mathematics, especially in statistics. When the function's parameter represents a probability , the logit function gives the log-odds, or the logarithm of the odds .〔(【引用サイトリンク】title=LOG ODDS RATIO )〕 ==Definition== The logit of a number ''p'' between 0 and 1 is given by the formula: : The base of the logarithm function used is of little importance in the present article, as long as it is greater than 1, but the natural logarithm with base e is the one most often used. The choice of base corresponds to the choice of logarithmic unit for the value: base 2 corresponds to a bit, base e to a nat, and base 10 to a ban (dit, hartley); these units are particularly used in information-theoretic interpretations. For each choice of base, the logit function takes values between negative and positive infinity. The "logistic" function of any number is given by the inverse-logit: : If ''p'' is a probability, then ''p''/(1 − ''p'') is the corresponding odds; the logit of the probability is the logarithm of the odds. Similarly, the difference between the logits of two probabilities is the logarithm of the odds ratio (''R''), thus providing a shorthand for writing the correct combination of odds ratios only by adding and subtracting: : 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「logit」の詳細全文を読む スポンサード リンク
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