```r
g0 <- ggplot(ragworm,aes(x=salinity,y=presence))
g1<-g0+geom_point()+stat_smooth(method="glm",formula = y~ x, method.args=list(family="binomial"))+ggtitle("Linear") 
g2<-g0+geom_point()+stat_smooth(method="glm",formula = y~ x+I(x^2), method.args=list(family="binomial"))+ggtitle("Polynomial")
g3<-g0+geom_point()+stat_smooth(method = "gam", formula = y ~ s(x), method.args=list(family="binomial"))+ggtitle("GAM")
multiplot(g1,g2,g3,cols=2)
```

<img src="qs_21_files/figure-html/unnamed-chunk-95-1.png" width="672" />