[R] using "aggregate" when variable names contain spaces

[Dimitri Liakhovitski]

That's helpful, thanks! Unfortunately, I cannot refer to all of my
variables to the left of tilda one by one - I have a lot of them.
Any way to get them in as a a bunch (somehow using mynames)?
Thanks!

On Mon, Apr 18, 2011 at 3:34 PM, David Winsemius <dwinsemius at comcast.net> wrote:
>
> On Apr 18, 2011, at 3:19 PM, Dimitri Liakhovitski wrote:
>
>> Hello!
>>
>> my data set has many variables. Unfortuantely, many of those variables
>> contain spaces in their names.
>> I need advice on: how to refer to variable names in the formula for
>> "aggregate". See example below:
>>
>> ### Generating example data set:
>> mydate = rep(seq(as.Date("2008-12-01"), length = 3, by = "month"),4)
>> value1=c(1,10,100,2,20,200,3,30,300,4,40,400)
>> value2=c(1.1,10.1,100.1,2.1,20.1,200.1,3.1,30.1,300.1,4.1,40.1,400.1)
>> example<-data.frame(mydate=mydate,value1=value1,value2=value2)
>>
>> example$group<-c(rep("group1",3),rep("group2",3),rep("group1",3),rep("group2",3))
>> exampe$group<-as.factor(exampe$group)
>>
>> ### Generating variable names with spaces:
>> names(example)<-c("mydate", "my value 1","my value 2","group")
>>
>> ### Trying to aggregate - but it's not working. Clearly, my reference
>> to variable names is incorrect:
>> mynames<-names(example)
>> example.agg1<-aggregate(cbind(mynames)~group+mydate,sum,data=example)
>
> Use backticks:
>
>> aggregate(`my value 1` + `my value 2` ~group+mydate,sum,data=example)
>   group     mydate `my value 1` + `my value 2`
> 1 group1 2008-12-01                         8.2
> 2 group2 2008-12-01                        12.2
> 3 group1 2009-01-01                        80.2
> 4 group2 2009-01-01                       120.2
> 5 group1 2009-02-01                       800.2
> 6 group2 2009-02-01                      1200.2
>>
>
>
> --
>
> David Winsemius, MD
> West Hartford, CT
>
>



-- 
Dimitri Liakhovitski
Ninah Consulting
www.ninah.com