Y-axis scale in Rstudio

[Maaike27]

I have a plot of the distribution of blood types in the Netherlands, but my y-axis is a bit messy as the values of A+ and O- are much larger than the rest (see picture). How can I get this right?

This is my code in Rstudio:
ggplot(data = Blood_types_Sanquin, mapping = aes(x=Bloodtype, y=Percentage))+
geom_bar(stat = "Identity")![Bloodtype%20distribution|689x462]

(upload://umNMkgIBjVrJevj1bYUF03lXiiw.png)

[andresrcs]

Hi, welcome!

To help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this guide, to see how to create one:

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.…

[Maaike27]

I do not completely understand the explanation about the reprex thing, but these are the values I want a graph of: (I called this dataframe Bloodtypes_3)

Bloodtype Percentage
A- 7
A+ 35
AB- 0,5
AB+ 2,5
B- 1,3
B+ 6,7
O- 7
O+ 39,5

ggplot(data = Bloodtypes_3, mapping = aes(x=Bloodtype, y=percentage))+
geom_bar(stat = "Identity")

With this piece of code I tried to make a bar plot with on the x-axis the bloodgroup (A-, A+ etc) and on the y-axis the percentages. But because the percentages of A+ and O+ are so big, it gives a messed up graph.
I hope this is enough, if not, please let me know. Really thank you for your help in advance

[andresrcs]

Have you read the link I gave you? sharing some sample data on a friendly format is as easy as typing datapasta::df_paste(Blood_types_Sanquin) and pasting the result here, also the link to the sample image you posted before is not working, could you fix that?

[Maaike27]

I indeed read the link, but I did not completely understand what I had to do. (I am just a beginner in Rstudio) But I tried what you said I had to do and this is the result:

Bloodtypes <- data.frame(stringsAsFactors=FALSE,
                         Bloodtype = c("A-", "A+", "AB-", "AB+", "B-", "B+",
                                       "O-", "O+"),
                         ABO = c("A", "A", "AB", "AB", "B", "B", "O", "O"),
                         Rhesus = c("-", "+", "-", "+", "-", "+", "-", "+"),
                         Percentage = c("7", "35", "0,5", "2,5", "1,3", "6,7", "7", "39,5"))
library(ggplot2)
ggplot(Bloodtypes, aes(x = Bloodtype, y = Percentage)) +
    geom_col()

^{Created on 2019-04-25 by the reprex package (v0.2.1)}

I hope the image works now.
Thank you for your help!

[andresrcs]

Yes, that was better, I have turned your data into a proper reprex to help you with that part, could you please elaborate a little more on what do you mean with "gives a messed up graph"? what would be your desired result?

[Maaike27]

I see now that the piece of code I used for making the bar is not copied correctly. This is the right code:
ggplot(data = Blood_types_Sanquin, mapping = aes(x=Bloodtype, y=Percentage))+
geom_bar(stat = "identity")

[Maaike27]

A+ and O+ have the highest values but the other bars with lower values are higher than them. This is because there is 35 and 39,5 between 2,5 and 6,7. I would like to know how to make a graph that looks like the image I shared before. (Idk how but it changed all of the sudden?!?)

[andresrcs]

Ok, I think I know what is going on here, the previous image changed because I edited your post to make it a proper reprex, the difference is that in the example I made, the decimal mark is a dot and in yours is a comma and R is treating them as a categorical variable (i.e. like text) you just have to use . instead of , as decimal mark.

[Maaike27]

I copied the code you edited in that post in my script and ran it, and it worked! This is the graph I was trying to make. Thank you so much for your help!

[andresrcs]

Just for completeness this would be the solution converting Percentage column from text to numeric.

Bloodtypes <- data.frame(stringsAsFactors=FALSE,
                         Bloodtype = c("A-", "A+", "AB-", "AB+", "B-", "B+",
                                       "O-", "O+"),
                         ABO = c("A", "A", "AB", "AB", "B", "B", "O", "O"),
                         Rhesus = c("-", "+", "-", "+", "-", "+", "-", "+"),
                         Percentage = c("7", "35", "0,5", "2,5", "1,3", "6,7", "7", "39,5"))

library(tidyverse)
Bloodtypes %>% 
    mutate(Percentage = parse_number(Percentage, locale = locale(decimal_mark = ","))) %>% 
    ggplot(aes(x = Bloodtype, y = Percentage)) +
    geom_col()

[RuReady]

One step further with fct_reorder

Bloodtypes %>% 
  mutate(Percentage = parse_number(Percentage, locale = locale(decimal_mark = ","))) %>% 
  ggplot(aes(x = fct_reorder(Bloodtype, Percentage, .desc = TRUE), y = Percentage)) +
  xlab('Bloodtype') +
  geom_col()