[R] Grouped Histogram (colored)

hadley wickham
Thu, 16 Oct 2008 16:59:40 -0000

On Thu, Oct 16, 2008 at 11:42 AM, x0rr0x <till.salzgeber at gmail.com>
wrote:
>
> Hi all,
>
> I'm trying to create a histogram which shows the frequency of variables
> within a certain timeframe.
>
> I've been using SPSS before, but I didn't quite like it...
>
> To describe my problem further here are some example variables:
>
> the "event" is actually a string which I recoded using:
> [code]
> data$event_class = as.numeric(as.factor(data$event))
> [/code]
> I've recoded them into numerics
>
>
> csv:
> [code]
> time,event,event_class
> 01,cookies,1
> 05,cookies,1
> 06,pie,2
> 07,coffee,3
> 08,cookies,1
> 30,pie,2
> 31,coffee,3
> [/code]
> and so on...
>
> Now I'd like to create a histogram where X is the time, the color of
the
> area is the event_class
> and Y is defined by the frequency of event_class around some accumulated
> time

install.packages("ggplot2")
library(ggplot2)

qplot(time, fill = event, data = mydata, geom = "histogram")

You can find out more about ggplot2 at http://had.co.nz/ggplot2 - it's
inspired by the Grammar of Graphics, which is also the theory that
underlies SPSS's plotting systems.

Hadley

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