Message-ID: <CADv2QyEi-=HHR5xkw_s_E5RembV9wnD8TUpGAUyzmbRtX9-FnQ@mail.gmail.com>
Date: 2013-03-28T22:08:21Z
From: Dennis Murphy
Subject: ggplot2: less than equal sign
In-Reply-To: <1364505750988-4662784.post@n4.nabble.com>
Hi:
Here's a way you could do it entirely within ggplot2. The annotation
functions have a parse = argument which allows you to pass character
string representations of math expressions, but there is no such thing
in the scale functions, so you need a different approach.
library(ggplot2)
df <- data.frame(vis=c(0,0,1,1) , count=c(10,15,20,10) , grp=c(0,1,0,1))
# Generate a list of expressions that will become the legend labels
lbs <- list(expression(x <= 10), expression(x > 10))
ggplot(df, aes(x = factor(vis), y=count , fill=factor(grp))) +
geom_bar(stat ="identity") +
scale_fill_manual(breaks = levels(factor(df$grp)),
values = c("blue", "orange"),
labels = lbs)
The specifications in scale_fill_manual() are:
- breaks: the values to go on the horizontal axis
- values: the vector of fill colors for each level of grp
- labels: the legend labels
Notice that the labels = takes a list of expressions as its argument.
This approach gives you more control over the legend and choice of
fill colors at the expense of a couple of lines of code. To change the
axis and legend titles, one can use the labs() function; e.g.,
last_plot() + labs(x = "Visibility", y = "Frequency", fill = "Threshold")
Dennis
On Thu, Mar 28, 2013 at 2:22 PM, soon yi <soon.yi at ymail.com> wrote:
> Hi
>
> I am trying to add a less than equal sign to a plot. I have previously done
> this using unicode but is not working in this instance. Any suggestions
> would be great
>
> thanks
>
> example code:
>
> library(ggplot2)
> df<-data.frame(vis=c(0,0,1,1) , count=c(10,15,20,10) , grp=c(0,1,0,1))
> df$grp <-factor(df$grp ,levels=c(0,1) , labels =c("x \u2265 10" , "x > 10"))
> ggplot(df, aes(x = factor(vis), y=count , fill=grp)) + geom_bar(stat =
> "identity")
>
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/ggplot2-less-than-equal-sign-tp4662784.html
> Sent from the R help mailing list archive at Nabble.com.
>
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