How to create a grouped bar chart in R with ggplot2's geom_col and position_dodge functions (CC107)

A grouped bar chart plot can be an effective way to represent the variation across a continuous variable for multiple levels of two categorical variables. These plots can be made in R using the geom_col and position_dodge functions from the ggplot2 R package. Watch this episode where Pat will demonstrate how to create barplots. Although these are superior to stacked barcharts, there are still problems with barcharts that he will discuss in this episode of Code Club.

Do you have a figure that you would like to receive a critique or help improving? Let me know and I'd be happy to arrange a guest appearance!

You can also find complete tutorials for learning R with the tidyverse using...

0:00 Introduction
5:56 Creating a grouped barchart
8:38 Deciding Which variable to group by on x-axis
14:09 Changing the plot to use genus data
22:57 Critique and Recap

[Riffomonas]

Anyone have anything to report back on their conversation with their PI or colleagues about using stacked vs grouped barcharts? Let us know what points were brought up!

[sitendugoswami]

At first broom::glance these videos may seem basic, but several of my peers sometimes struggle with formatting their graphs and this video can be really helpful in brushing up on the basics.

[getnetengdaw]

This is the best video. I always appreciate your teaching approach and explanation. please release videos on LULC or land use Land Cover Classification by using R. Thank You!

[jagdishthakur]

Thank you for these very helpful videos!

[alliejean]

Hi. I was hoping to work in parallel with your video so I can learn how to apply this to my data, but am having trouble finding where the code is in the GitHub folder. Can you please tell me how to find it? Thanks.

[ruiwang]

Hi, I have one question. How can we arrange the bars' position under the same variable. What if I want to swtich Healthy to the right, and Diarrhea C. to the left? Thank you!

[christophernavarrete]

How would I be able to change the order of the bars and the legend? Say for example, if I wanted to make "Healthy" the 3rd one down on the legend, and the third one in each group of columns? Like if I wanted the order to be Diarrhea, C. difficile positive; Diarrhea, C. difficile negative; Healthy?

[augustdinsen]

Hi! thank you for a great video, very helpful. I tried to add errorbars, but the errorbars center in the middle as though it is still a stacked bar chart. Is there a way of separating the errorbars and get them to center over their respective bar? I hope my question makes sense.

[guilhermesoares]

My grouped bar chart doesnt keep the order from column to column. I have searched everywhere and I still dont have a solution. Do you know what could be the problem ?

[minhtrungdang]

Thank you for the video. I just have a question regarding saving the output graph. I used R markdown and set the graph dimension, fig.height = 8, fig.width = 6 for example, to have a good size of graph. Of course, the font size are also adjusted in function of the dimension of the graph. However, when I used ggsave. The font size become much smaller, almost every thing. Could you give me some hints with that issue. I appreciate your help. Thank you!

[KN-txsd]

thanks, this is very helpful. Can I kindly request you if you could please put the details on how we can add ANOVA statistical significance as numerical or as asterisks above each grouped stacked bar.

[tylerminenube]

this video was so helpful! I have a question a made a facet graph with 16 small graphs, is there a way to separate them onto 16 different pages for easier viewing?

[ehtae]

Hi, your videos were very helpful to make figures with my own data. I made the relative abundance plot with geom_col but the plot were stacked by alphabetic order. Is there a way to reorder the stacked plot by legend order?

[richardsmith]

This guy is just doing these videos because he is trying to show off his knowledge.