Merge pull request hadley#127 from tomjamesprior/patch-2

Update variation.Rmd

variation.Rmd

@@ -418,7 +418,7 @@ ggplot(small_iris, aes(x = Sepal.Width, y = Sepal.Length)) +
   geom_point(aes(color = factor(clusters)))
 ```
 
-You can modify the hierarchical clustering algorithm by setting the method argument of hclust to one of "complete", "single", "average", or "centroid". The method determines how to measure the distance between two clusters or a lone point and a cluster, a measurement that effects the outcome of the algorithm.
+You can modify the hierarchical clustering algorithm by setting the method argument of hclust to one of "complete", "single", "average", or "centroid". The method determines how to measure the distance between two clusters or a lone point and a cluster, a measurement that affects the outcome of the algorithm.
 
 ```{r, echo = FALSE}
 knitr::include_graphics("images/EDA-linkage.pdf")