[R] How to use: library lattice: barchart

[Petr Pikal]

Hi

cbind(some numeric and not numeric columns)

gives you all columns to be character and when you make data.frame 
from it it is converted to factors.

so

> abarley = data.frame(ayield,avariety,ayear,asite)

brings you close but than you need ayear to be factor. Either convert 
it in data frame or on fly

barchart(ayield ~ avariety | asite, data = abarley, groups = 
factor(ayear), layout = c(1,5) )

HTH
Petr

BTW. If you encounter error other than 

"Error: syntax error in: ....

it's time to look at your data by

?str, class, typeoff, ...

and any other structure and type revealing tools.

Cheers.


On 21 Mar 2006 at 12:05, paladini at rz.uni-potsdam.de wrote:

Date sent:      	Tue, 21 Mar 2006 12:05:27 +0100
From:           	paladini at rz.uni-potsdam.de
To:             	r-help at stat.math.ethz.ch
Subject:        	[R] How to use: library lattice: barchart

> Dear ladies and gentlemen!
> 
> In the help text for the xyplot (library(lattice), help(xyplot)) is an
> example given how one can use barchart:
> 
> barchart(yield ~ variety | site, data = barley,
>               groups = year, layout = c(1,6),
>               ylab = "Barley Yield (bushels/acre)",
>               scales = list(x = list(abbreviate = TRUE,
>                             minlength = 5)))
> 
> I want my data to be represented just in the same way. But when I try
> it like this:
> 
> 
> ayield = c(2,3,5,6,3,4,7,8,9,2,3,5,6,1,2,3,4,2,6,8)
> avariety = c(rep("A",5),rep("B",5),rep("C",5),rep("D",5))
> ayear = (c(rep(1931,10),rep(1932,10)))
> asite = c(rep(c("iu","gt","jt","jhzt","tr"),4))
> abarley = data.frame(cbind(ayield,avariety,ayear,asite))
> 
> barchart(ayield ~ avariety | asite, data = abarley,groups = ayear,
> layout = c(1,5) )
> 
> it looks totaly different and I get the error message:
> "x should be numeric in: bwplot.formula(x = ayield ~ avariety | asite,
> data = list(ayield = c(2,"
> 
> What did I do wrong?
> Can anybody help me?
> 
> Best regards, thank you very much
> 
> 
> Claudia Paladini
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html

Petr Pikal
petr.pikal at precheza.cz