[R] Date Inconsistencies? Buglets?

[Gavin Simpson]

On Fri, 2010-08-20 at 10:35 -0400, ivo welch wrote:
> The treatment of dates seems to be a little inconsistent in R 2.11.1
> (2010-05-31):
<snip />
> 
> [2] How do dates on axes work?
> 
>   > plot( c(as.Date(1:20, origin="1970-01-01")), 1:20 )
>   > axis( side=3, c(as.Date(1:20, origin="1970-01-01")))
> 
> The lower axis is drawn from the plot() with dates.  The upper axis
> from axis() is drawn with numbers, not dates.

axis() isn't generic:

> methods(axis)
[1] axis.Date    axis.POSIXct
Warning message:
In methods(axis) : function 'axis' appears not to be generic

So you either have to call axis.Date directly or use the generic version
Axis()

plot( c(as.Date(1:20, origin="1970-01-01")), 1:20 )
axis.Date( side=3, c(as.Date(1:20, origin="1970-01-01")))

or

plot( c(as.Date(1:20, origin="1970-01-01")), 1:20 )
Axis( side=3, c(as.Date(1:20, origin="1970-01-01")))

Think of axis.Date as being just like read.table or read.csv: they
aren't the S3 methods of generic function 'read' for objects of class
"table" or "csv", they are functions in their own right.

> (PS: Is there an easier way to tell R that I want a whole lot more
> tick marks and/or labels than what it gives me by default?)

?axis.Date

?Axis.Date

But you need to supply the ticks locations and labels as with any axis
call.

HTH

G

> 
> regards,
> 
> /iaw
> 
> ----
> Ivo Welch (ivo.welch at brown.edu, ivo.welch at gmail.com)
> 
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