CODEWITHSUNDEEP
rplotggplot2bar-chart
Cec Jurczyk
Cec Jurczyk

Reputation: 87

Barchart with ggplot 2 y axis labels

I have a little problem with a ggplot barchart.

I wanted to make a barchart with ggplot2 in order to compare my Svolumes for my 4 stocks on a period of few months.

I have two problems:

The first one is that my y axis is wrong. My graph/data seems correct but the y axis don't "follow" as I thought it will contain another scale... I would to have to "total" number of my dataset svolumes, I think here it is writing my svolumes values. I don't know how to explain but I would like the scale corresponding to all of my data on the graph like 10,20,etc until my highest sum of svolumes.

There is my code:

Date=c(rep(data$date))
Subject=c(rep(data$subject))
Svolume=c(data$svolume)
Data=data.frame(Date,Subject,Svolume)

Data=ddply(Data, .(Date),transform,pos=cumsum(as.numeric(Svolume))-(0.5*(as.numeric(Svolume))))

ggplot(Data, aes(x=Date, y=Svolume))+
  geom_bar(aes(fill=Subject),stat="identity")+
  geom_text(aes(label=Svolume,y=pos),size=3)

and there is my plot:

my pbarchart

I helped with the question here

Finally, How could I make the same plot for each months please? I don't know how to get the values per month in order to have a more readable barchart as we can't read anything here...

If you have other ideas for me I would be very glad to take any ideas and advices! Maybe the same with a line chart would be more readable...? Or maybe the same barchart for each stocks ? (I don't know how to get the values per stock either...)

I just found how to do it with lines.... but once again my y axis is wrong, and it's not very readable....

linechart

Thanks for your help !! :)

Upvotes: 1

Views: 1708

Answers (1)

Boxuan
Boxuan

Reputation: 5157

Try adding the following line right before your ggplot function. It looks like your y-axis is in character.

[edit] Incorporate @user20650's comments, add as.character() first then convert to numeric.

Data$Svolume <- as.numeric(as.character(Data$Svolume))

To produce the same plot for each month, you can add the month variable first: Data$Month <- month(as.Date(Date)). Then add facet to your ggplot object.

ggplot(Data, aes(x=Date, y=Svolume) +
  ...
  + facet_wrap(~ Month)

For example, your bar chart code will be:

Data$Svolume <- as.numeric(as.character(Data$Svolume))
Data$Month <- month(as.Date(Date))
ggplot(Data, aes(x=Date, y=Svolume)) +
  geom_bar(aes(fill=Subject),stat="identity") +
  geom_text(aes(label=Svolume,y=pos),size=3) +
  facet_wrap(~ Month)

and your Line chart code will be:

Data$Svolume <- as.numeric(as.character(Data$Svolume))
Data$Month <- month(as.Date(Date))
ggplot(Data, aes(x=Date, y=Svolume, colour=Subject)) +
  geom_line() +
  facet_wrap(~ Month)

Upvotes: 2

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