Merge pull request #688 from jhudsl/images-added

Added Allison Horst's awesome illustrations

Author: avahoffman

modules/Data_Visualization/Data_Visualization.Rmd

@@ -112,6 +112,12 @@ Slide Credit: Tanya Shapiro
 
 -   [ggplot2 gallery](https://www.r-graph-gallery.com/ggplot2-package.html)
 
+```{r, fig.alt="ggplot with cartoon artists assembling works of art.", out.width = "40%", echo = FALSE, fig.show='hold',fig.align='center'}
+knitr::include_graphics("img/ggplot2_masterpiece.jpeg")
+```
+
+Artwork by @allison_horst. https://allisonhorst.com/
+
 ## Tidy data
 
 To make graphics using `ggplot2`, our data needs to be in a **tidy** format

modules/Data_Visualization/img/ggplot2_masterpiece.jpeg

@@ -279,6 +279,14 @@ wide <- long %>% pivot_wider(names_from = "name",
 wide
 ```
 
+## `gather()` and `spread()`
+
+```{r, fig.alt="Gather and spread functions in cartoon form.", out.width = "50%", echo = FALSE, align = "center"}
+knitr::include_graphics("images/gatherspread.jpeg")
+```
+
+Artwork by @allison_horst. https://allisonhorst.com/
+
 ## Summary
 
 - `tidyr` package (part of `tidyverse`) helps us convert between wide and long data