R help - Dec 2007 - Using boxplot in a daily time series

Hi all, 

I'm trying to plot my daily time series, with 3650 observations( 10 years),
with boxplot but I want 12 boxes, one for each month, can anyone help me doing
that.

Best regards

From your post it is not clear how the data are organized. Supposing 
they are in a data frame you could use the ~ sintax.

For example:
timeColumn=as.Date("01-01-1970") + 1:500
timeSeries=rnorm(500)
df=data.frame(time=timeColumn, index=timeSeries)
> > head(df)
>      time      index
> 1 1-01-20 -0.6382554
> 2 1-01-21 -2.0346649
> 3 1-01-22 -0.4900213
> 4 1-01-23  0.7311806
> 5 1-01-24  0.9386528
> 6 1-01-25  0.7868129
boxplot(index~months(time), data=df)

Perhaps you would order the 12 boxes according to the months:
monthColumn=ordered(months(df$time), levels= c("January",
"February",
"March",
            "April", "May", "June",
"July", "August", "September",
"October", "November", "December"))
boxplot(df$index~monthColumn)

domenico

pedrosmarques at portugalmail.pt wrote:
> Hi all, 
>
> I'm trying to plot my daily time series, with 3650 observations( 10
years), with boxplot but I want 12 boxes, one for each month, can anyone help me
doing that.
>
> Best regards
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>

On Saturday 15 December 2007 07:13:34 am pedrosmarques at portugalmail.pt
wrote:
> Hi all,
>
> I'm trying to plot my daily time series, with 3650 observations( 10
years),
> with boxplot but I want 12 boxes, one for each month, can anyone help me
> doing that.
>
> Best regards
>
Sure,

there are several approaches to this, but in general thinking about your data 
in terms of 'grouping' factors can be helpful

example:

# 1 year's worth of dates:
d <- strptime(1:365, format="%j")

# some simulated data
x <- rlnorm(365)

# combine them into a DF 
dx <- data.frame(date=d, value=x)

# plot the data, note that x-axis is in dates:
plot(dx)

# now generate a grouping factor. how about months:
dx$month <- format(dx$date, format="%B")

# box and whisker plot for data *grouped* by month
boxplot(value ~ month, data=dx, las=3)


cheers,

Dylan