geom_path: Each group consists of only one observation. Do you need to adjust the group aesthetic? error for Boxplot and geom_line

[Claragr]

Hi,

I'm trying to create a Boxplot with lines between dots of 2 conditions (PRE & POS) from an excel table. However, in this excel table, some rows are empty (cause of lack of data). I guess this is posing a problem for establishing my lines between my 2 conditions. Here is the script I used (working when I have fully filled excel rows):

data<-read_excel("Thelper PRE POS.xls")
Samples<-data$samples
Samples=as.factor(data$samples)
Samples
Th1<-data$Th1
condi<-data$condi
Condi=as.factor(data$condi)
Condi<-factor(c("pre","pos"))
dfdata<-data.frame(condi,Th1)

dfdata<-drop_na(dfdata)

p<-ggplot(dfdata,aes(x=reorder(condi,Th1),y=Th1))+
geom_boxplot(aes(fill=condi),width=0.4, size=1,fatten=0.3,colour="black")+
geom_point(size=2, colour="black")+
geom_line(aes(group=Samples),colour="grey",linetype="11")+
scale_fill_manual(values = c("#C3D7A4", "#CC79A7"))+
theme_classic()
p

Here is the error I get:
geom_path: Each group consists of only one observation. Do you need to adjust the group
aesthetic?

And lines are not present on my graphs:

What can be the problem?

Thanks a lot

[nirgrahamuk]

Hi!

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.…

---

Short Version

You can share your data in a forum friendly way by passing the data to share to the dput() function.
If your data is too large you can use standard methods to reduce it before sending to dput().
When you come to share the dput() text that represents your data, please be sure to format your post with triple backticks on the line before your code begins to format it appropriately.

```
( example_df <- structure(list(Sepal.Length = c(5.1, 4.9, 4.7, 4.6, 5, 5.4, 4.6, 
5, 4.4, 4.9), Sepal.Width = c(3.5, 3, 3.2, 3.1, 3.6, 3.9, 3.4, 
3.4, 2.9, 3.1), Petal.Length = c(1.4, 1.4, 1.3, 1.5, 1.4, 1.7, 
1.4, 1.5, 1.4, 1.5), Petal.Width = c(0.2, 0.2, 0.2, 0.2, 0.2, 
0.4, 0.3, 0.2, 0.2, 0.1), Species = structure(c(1L, 1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L), .Label = c("setosa", "versicolor", "virginica"
), class = "factor")), row.names = c(NA, -10L), class = c("tbl_df", 
"tbl", "data.frame")))
```