Fix spelling mistakes

NEWS.md

@@ -32,13 +32,13 @@ functions from the `qiimer` package.  Utility functions `dist_setNames` and
 `dist_make` were added to the existing functions `dist_subset`, `dist_get`, and
 `dist_groups`.
 
-The other area of focus for our inital release was a set of distance-to-centroid
-functions.  These functions operate on a set of items that are placed into
-several groups, and they apply algebraic formulas to find the group centroid
-distances based on the distance matrix.  If you had a set of points in normal
-Euclidean space, you could easily find the centroid positions and compute the
-distances from there.  The centroid functions included in the package are more
-useful for non-Euclidean distances, where it is less striaghtforward to locate
-the centroids in space.  The centroid functions were inspired by work in
-microbial ecology, where it is typical to work with non-Euclidean distances
-between samples.
+The other area of focus for our initial release was a set of
+distance-to-centroid functions.  These functions operate on a set of items
+that are placed into several groups, and they apply algebraic formulas to find
+the group centroid distances based on the distance matrix.  If you had a set
+of points in normal Euclidean space, you could easily find the centroid
+positions and compute the distances from there.  The centroid functions
+included in the package are more useful for non-Euclidean distances, where it
+is less straightforward to locate the centroids in space.  The centroid
+functions were inspired by work in microbial ecology, where it is typical to
+work with non-Euclidean distances between samples.

README.Rmd

@@ -215,7 +215,7 @@ data_matrix
 Note that we provide bare column names in the call to
 `pivot_to_numeric_matrix()`. This function requires some extra packages to
 be installed.  They are listed as suggestions for `usedist`.  If the
-aditional packages are not installed on your system, you'll get an error
+additional packages are not installed on your system, you'll get an error
 message with the missing packages listed.
 
 The matrix format is what we need for distance calculations. If you want to

README.md

@@ -300,8 +300,8 @@ data_matrix
 Note that we provide bare column names in the call to
 `pivot_to_numeric_matrix()`. This function requires some extra packages
 to be installed. They are listed as suggestions for `usedist`. If the
-aditional packages are not installed on your system, you’ll get an error
-message with the missing packages listed.
+additional packages are not installed on your system, you’ll get an
+error message with the missing packages listed.
 
 The matrix format is what we need for distance calculations. If you want
 to convert from long format and use a custom distance function, you can