[R] Adjusting axis labels on lattice xyplot

[Rich Shepard]

On Fri, 14 Oct 2016, David Winsemius wrote:

>> rain <- source("~/raindata.dat")
>> str(rain)
> List of 2
> $ value  :'data.frame':	341 obs. of  3 variables:
>  ..$ station: Factor w/ 6 levels "0.3E","0.6W",..: 1 1 1 1 1 1 1 1 1 1 ...
>  ..$ date   : Factor w/ 62 levels "2013-12-01","2013-12-02",..: 32 33 34 35 36 37 38 39 40 41 ...
>  ..$ amount : Factor w/ 48 levels "","0.00","0.01",..: 1 1 3 2 2 2 12 18 34 14 ...
> $ visible: logi TRUE

David,

   I left the station as a factor and changed the date using
as.Date(as.character...) and the amount using as.numeric.

> When you do that you can see the only the first item in the length2 list
> is likely to be useful:

   I'm not seeing to what the 'List of 2' refers in the data.frame.

   This is the script I sourced:

rain <- read.csv("daily_records.csv", header=T, sep=",")
require(lattice)
rain$date <- as.Date(as.character(rain$date))
rain$amount <- as.numeric(rain$amount)
xyplot(rain$amount ~ rain$date | rain$station, main="Weather Stations", xlab="Date", ylab="Amount (inches)", pch=20, col=132)

   What did I do incorrectly here?

> And the date column is a factor. Fortunately the as.Date.factor function
> doesn't need as.chaacter anymore:

   Oh. Thanks.

> The place on the ?xyplot help page to look is in the section on `scales`.
> There's no difficulty using 'rot' as long as it is in the correct place
> which in this instance is `x` sublist of the `scales` list

> xyplot(amount ~ date | station, data=rain, main="Weather Stations",
>    xlab="Date", ylab="Amount (inches)", pch=16, col=132,
>    scales=list(y=list(at=0:4),
>                x=list(at=seq(min(rain$date), max(rain$date), by='week'), rot=90) )
>      )

   That's what I missed: where the scales command is placed, and
understanding how to use all the components.

   I need to figure out why I'm no longer seeing the help files. As far as I
know they should be loaded when I invoke R.

Thanks very much,

Rich