[R] Stripchart: way to get different colour for each group

[johannes rara]

I was probably too vague. I meant that the group variable descirbes
the group (eg. different individuals) and val1 and val2 are just two
variables measured from eg. individual.

> mydata
   val1 val2 group
1   1.1  4.2     0
2   3.2  5.3     1
3   4.1  3.4     0
4   2.5  2.6     1
5   6.2  5.3     0
6   5.3  6.2     1
7   4.5  7.7     0
8   2.2  4.8     1
9   4.7  3.4     0
10  2.7  2.1     1


So, I want to color the points of those groups using different colour.

- J

2009/12/1 David Winsemius <dwinsemius at comcast.net>:
>
> On Dec 1, 2009, at 12:42 AM, johannes rara wrote:
>
>> Hi,
>>
>> Is there a way to get different colour based on group when plotting
>> stripchart?
>>
>> mydata <- data.frame(val1 = c(1.1, 3.2, 4.1, 2.5, 6.2, 5.3, 4.5, 2.2,
>> 4.7, 2.7), val2 = c(4.2, 5.3, 3.4, 2.6, 5.3, 6.2, 7.7, 4.8, 3.4, 2.1),
>> group = rep(0:1, 5))
>> mydata.stack <- stack(mydata, select=-group)
>>
>> stripchart(values ~ ind,
>>         data=mydata.stack,
>>         vertical=T,
>>         at=c(1.25, 1.75),
>>         pch=15,
>>         col="red")
>>
>> I would like to get different colour for the two groups (based on
>> group variable). I tried something like
>>
>> stripchart(values ~ ind,
>>         data=mydata.stack,
>>         vertical=T,
>>         at=c(1.25, 1.75),
>>         pch=15,
>>         col=c("red", "yeallow")[mydata$group])
>
> Doesn't this work?
>
> stripchart(values ~ ind,
>         data=mydata.stack,
>         vertical=T,
>         at=c(1.25, 1.75),
>         pch=15,
>         col=c("red", "yellow") )
>
> I would not think that mydata$group would be "in sync" with the dataset that
> you are passing to stripchart.
>
> --
> David
>
> David Winsemius, MD
> Heritage Laboratories
> West Hartford, CT
>
>