add data and instructor note

episodes/basic-gis-operations-with-sf.md

@@ -26,7 +26,7 @@ encode spatial vector data."](https://cran.r-project.org/web/packages/sf/sf.pdf)
 It contains a large set of functions to achieve all the operations on vector spatial data for which you might use traditional GIS software: change the coordinate system, join layers, intersect or unite polygons, create buffers and centroids, etc. cf. the `sf` [cheatsheet](https://raw.githubusercontent.com/rstudio/cheatsheets/main/sf.pdf).
 
 
-## Conservation in Brielle, NL
+### Conservation in Brielle, NL
 
 Let's focus on old buildings and imagine we're in charge of their conservation. We want to know how much of the city would be affected by a non-construction zone of 100m around pre-1800 buildings.
 
@@ -117,7 +117,7 @@ Now what we would like to distinguish conservation areas based on the number of
                         option = "B")
 ```
 
-## Final output:
+### Final output:
 
 Let's map this layer over the initial map of individual buildings.
 

episodes/data/boundingboxBrielle.prj

@@ -0,0 +1 @@
+GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]]

episodes/data/dataBrielle.prj

@@ -0,0 +1 @@
+PROJCS["RD_New",GEOGCS["GCS_Amersfoort",DATUM["D_Amersfoort",SPHEROID["Bessel_1841",6377397.155,299.1528128]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Double_Stereographic"],PARAMETER["False_Easting",155000.0],PARAMETER["False_Northing",463000.0],PARAMETER["Central_Meridian",5.38763888888889],PARAMETER["Scale_Factor",0.9999079],PARAMETER["Latitude_Of_Origin",52.1561605555556],UNIT["Meter",1.0]]

episodes/import-and-visualise-data-from-open-street-map.md

@@ -73,6 +73,14 @@ bb
 
 
 
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+If this does work for some reason, the `nominatim_polygon` can be found in the data folder: "episodes/data/boundingboxBrielle.shp".
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 ## Extracting features
 
 A [feature](https://wiki.openstreetmap.org/wiki/Map_features) in the OSM language is a category or tag of a geospatial object. Features are described by general keys (e.g. "building", "boundary", "landuse", "highway"), themselves decomposed into sub-categories (values) such as "farm", "hotel" or "house" for `buildings`, "motorway", "secondary" and "residential" for `highway`. This determines how they are represented on the map.
@@ -130,6 +138,14 @@ buildings <- x$osm_polygons %>%
   st_transform(.,crs=28992)
 ```
 
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+If this does work for some reason, the `buildings` can be found in the data folder: "episodes/data/dataBrielle.shp".
+
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 ### Visualisation
 
 Then we create a variable which a threshold at 1900. Every date prior to 1900 will be recoded 1900, so that buildings older than 1900 will be represented with the same shade.
@@ -188,15 +204,6 @@ leaflet(buildings2) %>%
 
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-Inline instructor notes can help inform instructors of timing challenges
-associated with the lessons. They appear in the "Instructor View"
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 ::::::::::::::::::::::::::::::::::::: keypoints 
 
 - Use the `Nominatim` and `OverPass` APIs within R