[R] Adding Year-Month-Day to X axis

[Gregory Coats]

Jim,
Thank you very much!
How do I use the axis command for side=1 to label the x horizontal axis, in the format="%Y-%m-%d” style?
Greg

y_duration <- c (301.59050,  387.35700,  365.64366,  317.26150,  321.71883,  342.44950,  318.95350,  322.33233,  330.60333,  428.99516,  297.82066,  258.23166)
x_yyyymmdd <-as.Date(c ("2018-04-25", "2018-04-26", "2018-04-27", "2018-04-28", "2018-04-29", "2018-04-30", "2018-05-01", "2018-05-02", "2018-05-03", "2018-05-04", "2018-05-05", "2018-05-06"), format="%Y-%m-%d")
plot   (x_yyyymmdd, y_duration, type="l", xaxt="n", yaxt="n", ylim=range(240,480))
abline (h=c(240,270,300,330,360,390,420,450,480,510,540), lty=2, lwd=1.0, col="grey40")
axis   (side=2, at=240,  cex.axis=1.0, label="4:00")
axis   (side=2, at=300,  cex.axis=1.0, label="5:00")
axis   (side=2, at=360,  cex.axis=1.0, label="6:00")
axis   (side=2, at=420,  cex.axis=1.0, label="7:00")
axis   (side=2, at=480,  cex.axis=1.0, label="8:00")

> On May 6, 2018, at 3:52 AM, Jim Lemon <drjimlemon using gmail.com> wrote:
> 
> Hi Greg,
> By default, the "axis" function puts the labels on one line and drops
> labels that would overlap. When you have labels that are all the same
> length, this usually results in every second, or third, or fourth
> label being displayed. So you can probably get what you want by not
> using staxlab. However, if you really want to use staxlab, try this:
> 
> oddones<-seq(1,length(x_yyyymmdd)-1,by=2)
> staxlab(1,at=x_yyyymmdd[oddones],
> labels=format(x_yyyymmdd,"%Y-%m-%d")[oddones])
> 
> It will also work with plain "axis", which is what you seem to want.
> 
> Jim


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