```r
slope<-terrain(dtm, opt='slope', unit='degrees')
aspect<-terrain(dtm, opt='aspect',unit='degrees')
sloper<-terrain(dtm, opt='slope', unit='radians')
aspectr<-terrain(dtm, opt='aspect',unit='radians')
hillshade<-hillShade(sloper,aspectr,angle=5)


plot(hillshade, col = gray(0:100 / 100), legend = FALSE)
plot(dtm, col = terrain.colors(25), alpha = 0.3, legend = TRUE, add = TRUE)
```

<img src="Quantitative_and_Spatial_files/figure-html/unnamed-chunk-215-1.png" width="672" />