how to show in ggplot overlapping points as "segmented" points
<p>I have following problem, in my data set I have for identical dates results from different devices. I want to do a plot wit dat on x axis, result on y axis (which is either 0 or 1) ann the colour coded by the number of device.
I found the solution with plotting the points with position_dodge.
I would like to have per point consisiting of different results a "segmented" point constituted of the different colour codes by device number.</p>

<p>Can anyone help me with that issue?</p>

<p>A short example:</p>

<pre><code>library(ggplot2)
test &lt;-data.frame(device=c(1,1,2,2,3,3), date=c("2011-02-15", "2012-02-15", "2011-02-15", "2012-03-12", "2011-02-15", "2012-03-12"), result=c(1,0,1,0,0,1)) 

test$device&lt;-as.factor(test$device)

theme_set(theme_bw(16))

p &lt;-ggplot(aes(x = date, y = result, colour=device), data = test) +
    geom_point(position=position_dodge(width = 0.1),size=5) +
    xlab("date") +
    ylab("result") +
    scale_y_continuous(breaks=c(0,1))

p + theme(axis.text.x = element_text(angle = 90,vjust = 0.5, hjust = 0))
</code></pre>