Added DEM to graphs showing position of strange plots (elevation < -100)

code/01_Extract_elevation.Rmd

@@ -38,7 +38,8 @@ library(viridis)
 library(grid)
 library(gridExtra)
 library(ggforce)
-
+library(viridis)
+library(ggrepel)
 ```
 
 
@@ -235,7 +236,7 @@ summary(elevation.out)
 
 ```
 
-There are `r sum(elevation.out$elevation < -100)` plots with elevation < 100 !  
+There are `r sum(elevation.out$elevation < -100, na.rm=T)` plots with elevation < -100 !  
   
 Check strange values (elevation < -100 m.s.l.)
 
@@ -271,16 +272,27 @@ strange <- strange %>%
 for(i in 1:nlevels(strange$tilenam)){
   strange.i <- strange %>%
     filter(tilenam==levels(strange$tilenam)[i])
+  sp.i <- SpatialPoints(coords=strange.i %>%
+                          dplyr::select(Longitude, Latitude),
+                        proj4string = CRS("+init=epsg:4326"))
+  dem.i <- get_elev_raster(sp.i, z=10)
+  dem.df <- data.frame(xyFromCell(dem.i, cell=1:ncell(dem.i)), z=getValues(dem.i))
+  
   ggstrange <- ggplot(countries, aes(x=long, y=lat, group = group)) +
-    geom_polygon(col=gray(0.3), lwd=0.3, fill = gray(0.9)) + 
+    geom_tile(data=dem.df, aes(x=x, y=y, colour=z, group=1)) + 
+    geom_polygon(col=gray(0.3), lwd=0.3, fill = gray(0.9), alpha=1/5) + 
     geom_point(data=strange.i, 
-              aes(x=Longitude, y=Latitude, group=1), col=2)+ 
+              aes(x=Longitude, y=Latitude, group=1), col="red")+ 
     coord_equal(xlim= robust.range(strange.i$Longitude),
                     ylim= robust.range(strange.i$Latitude)) + 
-    geom_label(data=strange.i, 
+    geom_label_repel(data=strange.i, 
               aes(x=Longitude, y=Latitude, group=1,
                   label=strange.i$PlotObservationID), 
-              nudge_y = 0.5)
+                  box.padding   = 0.35, 
+                  point.padding = 0.5,
+                  segment.color = 'grey50') +
+    
+    scale_color_viridis() + 
     theme_bw()  + 
     theme(axis.title = element_blank())
   print(ggstrange)