在R中绘制Logistic回归

Scott Davis 发表于 Dev

斯科特·戴维斯

如何绘制逻辑回归？我想在y轴上绘制因变量，在x上绘制因变量。我调用了系数并得到了输出，因此脚本上没有错误。

这是自变量（SupPres）的数据：

#Set the range for water supply pressure
SupPres <- c(20:120)
#Create a normal distribution for water supply pressure
SupPres <- rnorm(3000, mean=70, sd=25)

逻辑回归和创建y变量：

#Create logistic regression
z=1+2*NozHosUn+3*SupPres+4*PlaceSet+5*Hrs4+6*WatTemp
z <- (z-mean(z))/sd(z)
pr = 1/(1+exp(-z))
y <- rbinom(3000,1,pr)
DishWa=data.frame(y=y, NozHosUn=NozHosUn,SupPres=SupPres,
               PlaceSet=PlaceSet,Hrs4=Hrs4,WatTemp=WatTemp)
glm(y~NozHosUn+SupPres+PlaceSet+Hrs4+WatTemp, data=DishWa, 
    family=binomial)

如果可以提供更多信息，请告诉我。谢谢。

尤迪特里希

以下代码是一个可能的解决方案，该解决方案在Michael J. Crawley的绝妙著作《统计：使用R进行介绍》中提出了建议：

attach(mtcars);
model <- glm(formula = am ~ hp + wt, family = binomial);
print(summary(model));
model.h <- glm(formula = am ~ hp, family = binomial);
model.w <- glm(formula = am ~ wt, family = binomial);
op <- par(mfrow = c(1,2));
xv <- seq(0, 350, 1);
yv <- predict(model.h, list(hp = xv), type = "response");
hp.intervals <- cut(hp, 3);
plot(hp, am);
lines(xv, yv);
points(hp,fitted(model.h),pch=20);
am.mean.proportion <- tapply(am, hp.intervals, sum)[[2]] / table(hp.intervals)[[2]];
am.mean.proportion.sd <- sqrt(am.mean.proportion * abs(tapply(am, hp.intervals, sum)[[3]] - tapply(am, hp.intervals, sum)[[1]]) / table(hp.intervals)[[2]]);
points(median(hp), am.mean.proportion, pch = 16);
lines(c(median(hp), median(hp)), c(am.mean.proportion - am.mean.proportion.sd, am.mean.proportion + am.mean.proportion.sd));
xv <- seq(0, 6, 0.01);
yv <- predict(model.w, list(wt = xv), type = "response");
wt.intervals <- cut(wt, 3);
plot(wt, am);
lines(xv, yv);
points(wt,fitted(model.w),pch=20);
am.mean.proportion <- tapply(am, wt.intervals, sum)[[2]] / table(wt.intervals)[[2]];
am.mean.proportion.sd <- sqrt(am.mean.proportion * abs(tapply(am, wt.intervals, sum)[[3]] - tapply(am, wt.intervals, sum)[[1]]) / table(wt.intervals)[[2]]);
points(median(wt), am.mean.proportion, pch = 16);
lines(c(median(wt), median(wt)), c(am.mean.proportion - am.mean.proportion.sd, am.mean.proportion + am.mean.proportion.sd));
detach(mtcars);
par(op);