Try it like this:
Sheet <- data.frame(Group = gl(2, 50, labels=c("Group1", "Group2")),
MyValue = runif(100))
boxplot(MyValue ~ Group, data=Sheet)
Question
I am looking for the most convenient way of creating boxplots for different values and groups read from a CSV file in R.
First, I read my Sheet into memory:
Sheet <- read.csv("D:/mydata/Table.csv", sep = ";")
Which just works fine.
names(Sheet)
gives me correctly the Headlines of the different columns.
I can also access and filter different groups into separate lists, like
myData1 <- Sheet[Sheet$Group == 'Group1',]$MyValue
myData2 <- Sheet[Sheet$Group == 'Group2',]$MyValue
...
and draw a boxplot using
boxplot(myData1, myData2, ..., main = "Distribution")
where the ... stand for more lists I have filled using the selection method above.
However, I have seen that using some formular could do these steps of selection and boxplotting in one go. But when I use something like
boxplot(Sheet~Group, Sheet)
it won't work because I get the following error:
invalid type (list) for variable 'Sheet'
The data in the CSV looks like this:
No;Gender;Type;Volume;Survival
1;m;HCM;150;45
2;m;UCM;202;103
3;f;HCM;192;5
4;m;T4;204;101
...
So i have multiple possible groups and different values which I'd like to represent as a box plot for each group. For example, I could group by gender or group by type.
How can I easily draw multiple boxes from my CSV data without having to grab them all manually out of the data?
Thanks for your help.
Solution
Try it like this:
Sheet <- data.frame(Group = gl(2, 50, labels=c("Group1", "Group2")),
MyValue = runif(100))
boxplot(MyValue ~ Group, data=Sheet)
OTHER TIPS
Using ggplot2
:
ggplot(Sheet, aes(x = Group, y = MyValue)) +
geom_boxplot()
The advantage of using ggplot2
is that you have lots of possibilities for customizing the appearance of your boxplot.