我有对数观测值y(0,1)和两个自变量(x1和x2)的逻辑回归。我想通过热图(2D中的预测值矩阵)可视化模型预测。我可以部分得到我想要的东西(见下图),但是如何添加:
- 色标到预测值
- 合适的轴(水平和垂直) 垂直)用于x1和x2
- 我如何知道矩阵的适当旋转? x1(或x2)在水平或垂直轴上吗?
...
# data simulation
set.seed(16)
x_sample.lr <- seq(1,100,by = 0.5)
# data.frame creation
lr.df <- data.frame(y = sample(c(0,1),50,replace = TRUE),x1 = sample(x_sample.lr,x2 = sample(x_sample.lr,replace = TRUE))
# model creation
lr.mod <- glm(y ~ x1*x2,data = lr.df,family = "binomial")
anova(lr.mod,test = "Chi")
summary(lr.mod)
# ...calculating prediction
lr.pred <- expand.grid(x1 = x_sample.lr,x2 = x_sample.lr)
lr.pred$predicted <- predict(lr.mod,newdata = lr.pred)
head(lr.pred)
# x1 x2 predicted
# 1 1.0 1 2.306825
# 2 1.5 1 2.279347
# 3 2.0 1 2.251869
# ...plot visualization
pl.pred.mtrx <- matrix(lr.pred$predicted,ncol = sqrt(nrow(lr.pred)))
image(pl.pred.mtrx)