```r
new.mod<-lm(growth~tannin)
plot(growth~tannin)
lines(tannin,predict(mod,list(tannin)))
lines(tannin,predict(new.mod,list(tannin)),col=2)
```

<img src="Quantitative_and_Spatial_files/figure-html/unnamed-chunk-120-1.png" width="672" />