related to #798

05-geometry-operations.Rmd

@@ -463,23 +463,23 @@ plot(us_southhwest)
 
 \index{vector!geometry casting} 
 Geometry casting is a powerful operation that enables transformation of the geometry type.
-It is implemented in the `st_cast` function from the **sf** package.
-Importantly, `st_cast` behaves differently on single simple feature geometry (`sfg`) objects, simple feature geometry column (`sfc`) and simple features objects.
+It is implemented in the `st_cast()` function from the **sf** package.
+Importantly, `st_cast()` behaves differently on single simple feature geometry (`sfg`) objects, simple feature geometry column (`sfc`) and simple features objects.
 
 Let's create a multipoint to illustrate how geometry casting works on simple feature geometry (`sfg`) objects:
 
 ```{r 05-geometry-operations-28}
 multipoint = st_multipoint(matrix(c(1, 3, 5, 1, 3, 1), ncol = 2))
 ```
 
-In this case, `st_cast` can be useful to transform the new object into linestring or polygon (Figure \@ref(fig:single-cast)):
+In this case, `st_cast()` can be useful to transform the new object into a linestring or a polygon (Figure \@ref(fig:single-cast)):
 
 ```{r 05-geometry-operations-29}
 linestring = st_cast(multipoint, "LINESTRING")
 polyg = st_cast(multipoint, "POLYGON")
 ```
 
-```{r single-cast, echo = FALSE, fig.cap="Examples of linestring and polygon casted from a multipoint geometry.", warning=FALSE, fig.asp=0.3, fig.scap="Examples of casting operations."}
+```{r single-cast, echo = FALSE, fig.cap="Examples of a linestring and a polygon casted from a multipoint geometry.", warning=FALSE, fig.asp=0.3, fig.scap="Examples of casting operations."}
 p_sc1 = tm_shape(st_sfc(multipoint)) + tm_symbols(shape = 1, col = "black", size = 0.5) +
   tm_layout(main.title = "MULTIPOINT", inner.margins = c(0.05, 0.05, 0.05, 0.05))
 p_sc2 = tm_shape(st_sfc(linestring)) + tm_lines() +
@@ -490,10 +490,10 @@ tmap_arrange(p_sc1, p_sc2, p_sc3, ncol = 3)
 ```
 
 Conversion from multipoint to linestring is a common operation that creates a line object from ordered point observations, such as GPS measurements or geotagged media.
-This allows spatial operations such as the length of the path traveled.
+This, in turn, allows to perform spatial operations such as the calculation of the length of the path traveled.
 Conversion from multipoint or linestring to polygon is often used to calculate an area, for example from the set of GPS measurements taken around a lake or from the corners of a building lot.
 
-The transformation process can be also reversed using `st_cast`:
+The transformation process can be also reversed using `st_cast()`:
 
 ```{r 05-geometry-operations-30}
 multipoint_2 = st_cast(linestring, "MULTIPOINT")
@@ -503,8 +503,8 @@ all.equal(multipoint, multipoint_3)
 ```
 
 ```{block2 05-geometry-operations-31, type='rmdnote'}
-For single simple feature geometries (`sfg`), `st_cast` also provides geometry casting from non-multi-types to multi-types (e.g., `POINT` to `MULTIPOINT`) and from multi-types to non-multi-types.
-However, only the first element of the old object would remain in the second group of cases.
+For single simple feature geometries (`sfg`), `st_cast()` also provides geometry casting from non-multi-types to multi-types (e.g., `POINT` to `MULTIPOINT`) and from multi-types to non-multi-types.
+However, when casting from multi-types to non-multi-types only the first element of the old object would remain in the output object.
 ```
 
 ```{r 05-geometry-operations-32, include=FALSE}
@@ -516,9 +516,9 @@ t = cast_all(multipoint)
 t2 = cast_all(polyg)
 ```
 
-Geometry casting of simple features geometry column (`sfc`) and simple features objects works the same as for single geometries in most of the cases. 
+Geometry casting of simple features geometry column (`sfc`) and simple features objects works the same as for `sfg` in most of the cases. 
 One important difference is the conversion between multi-types to non-multi-types.
-As a result of this process, multi-objects are split into many non-multi-objects.
+As a result of this process, multi-objects of `sfc` or `sf` are split into many non-multi-objects.
 
 Table \@ref(tab:sfs-st-cast) shows possible geometry type transformations on simple feature objects.
 Each input simple feature object with only one element (first column) is transformed directly into another geometry type.
@@ -562,7 +562,7 @@ multilinestring_sf
 You can imagine it as a road or river network. 
 The new object has only one row that defines all the lines.
 This restricts the number of operations that can be done, for example it prevents adding names to each line segment or calculating lengths of single lines.
-The `st_cast` function can be used in this situation, as it separates one mutlilinestring into three linestrings:
+The `st_cast()` function can be used in this situation, as it separates one mutlilinestring into three linestrings:
 
 ```{r 05-geometry-operations-34}
 linestring_sf2 = st_cast(multilinestring_sf, "LINESTRING")