不同的模型有不同的链接函数。要计算预测值,请对模型的链接函数求逆。逆函数位于下表中。
模型 | 链接函数 | 预测公式 |
---|---|---|
二项 | Logit(L) | |
二项 | Normit | |
二项 | Gompit | |
Poisson | 自然对数 | |
Poisson | 平方根 | |
Poisson | 致命ID |
项 | 说明 |
---|---|
exp(·) | 指数函数 |
Φ(·) | 正态分布的累积分布函数 |
X' | 要预测的点的向量转置 |
估计的系数的向量 |
其中 仅从训练数据,只有当有一个测试数据集进行验证时。
项 | 说明 |
---|---|
1, for the binomial and Poisson models | |
xi | the vector of a design point |
the transpose of xi | |
X | the design matrix |
W | the weight matrix |
the first derivative of the link function evaluated at | |
the predicted mean response | |
the predicted probability for the design point in a binary logistic model | |
the inverse cumulative distribution function of the standard normal distribution for the predicted probability in a binary logistic model | |
the probability density function of the standard normal distribution |
置信限使用 Wald 近似法。以下是 100(1 | α双侧置信区间
类型 | 链接 | 拟合值的标准误 |
---|---|---|
二值 Logistic | Logit | |
二值 Logistic | Normit | |
二值 Logistic | Gompit | |
Poisson | 对数 | |
Poisson | 平方根 | |
Poisson | 标识 |
其中 仅从训练数据,只有当有一个测试数据集进行验证时。
项 | 说明 |
---|---|
the inverse of the link function evaluated at x | |
the transpose of the vector of the predictors | |
the vector of estimated coefficients | |
the value of the inverse cumulative distribution function for the normal distribution evaluated at | |
α | the significance level |
X | the design matrix |
W | the weight matrix |
1, for binomial and Poisson models | |
the predicted probability for the design point in a binary logistic model | |
the inverse cumulative distribution function of the standard normal distribution for the predicted probability in a binary logistic model | |
the cumulative distribution function of the standard normal distribution |