多分类对数几率回归与二分类的对数几率回归不同的是,不再使用逻辑函数(Logistic Function),而是使用Softmax函数2(Softmax Function),该函数可以看作是对逻辑函数的一种推广。 Softmax函数能将一个含任意实数的K维向量z“压缩”到另一个K维实向量σ(z)中,使得每一个元素的范围都在(0,1)之间,并...
https://en.wikipedia.org/wiki/Multinomial_logistic_regression (look at "Note that not all of the \beta_k vectors of coefficients are uniquely identifiable."). You can multiply (or add a constant to) the outcome mu vector and not change the result of the softmax. I'm not sure which th...
9 RegisterLog in Sign up with one click: Facebook Twitter Google Share on Facebook multinomial Thesaurus Medical Encyclopedia Wikipedia mul·ti·no·mi·al (mŭl′tĭ-nō′mē-əl) n. Seepolynomial. [multi-+(bi)nomial.] mul′ti·no′mi·aladj. ...