[R] plotting date data over couple of months

[David Winsemius]

On Jul 13, 2011, at 8:32 PM, vamshi999 wrote:

> I am sorry again..
>
> I am posting the sample data..
>
> my data set is huge.. dimension of my data set is 50000 x 6
>   scan.no    bird.no             date                   time
> height
> "1"	24	       5		"2011-04-29"	"21:17:56"      357
> "2"	78	     48		"2011-04-29"	"21:20:08"      131
> "3"	61	    105		"2011-04-29"	"21:24:58"      432
> "4"	64	    122		"2011-04-29"	"21:25:05"      673
> "5"	64	    124		"2011-04-30"	"21:25:05"      123
> "6"	64	    121		"2011-04-30"	"21:25:05"      479
> "7"	65	    123		"2011-05-03"	"21:25:07"      269
> "8"	73	    380		"2011-05-03"	"21:25:40"      131
> "9"	79	  1073		"2011-05-05"	"21:25:41"      356
> "10"	82	  1093		"2011-05-05"	"21:26:24"      378
> "11"	82	  1101		"2011-05-05"	"21:27:30"      412
>
> I have dates values from april and whole month of may (except some  
> days..
> when i was not able to record the data)
>

You are exhibiting discourteous posting behavior by failing to include  
context. Nabble is not r-help. Read the Posting Guide.

Here is a worked example using base plotting functions. The data was  
read into a dataframe with this structure:

 > str(dat)
'data.frame':	11 obs. of  5 variables:
  $ scan.no: num  24 78 61 64 64 64 65 73 79 82 ...
  $ bird.no: num  5 48 105 122 124 ...
  $ date   : Date, format: "2011-04-29" "2011-04-29" ...
  $ time   : chr  "21:17:56" "21:20:08" "21:24:58" "21:25:05" ...
  $ height : num  357 131 432 673 123 479 269 131 356 378 ...


plot(dat$date, dat$height, xaxt="n")
  axis(1, at=dat$date[c(1,11)],     # only plot beginning and ending  
month names
         labels=month.abb[ 1+as.POSIXlt(dat$date[c(1,11)])$mon], # add  
1 to index
                              # the month.abb constant vector
         line=2,              # shifts these down
         lwd=0)  # this sppress the extra axis lines
  axis(1, at=dat$date, labels=as.POSIXlt(dat$date)$mday)  # plot the  
days

The aggregate function could be used to calculate daily means and sd's  
you mentioned in an earlier posting.

-- 

David Winsemius, MD
West Hartford, CT