R help - Jan 2003 - plot()

I am an R novice trying to figure out plot(). 
Specifically, I am trying to plot the values of a
numeric variable V for a set of years (1970, 1974,
1976, 1978, 1980).  How do I get R to label the years
I am plotting on the x-axis rather then some general
levels (1970, 1975, 1980.)  Using as.character(year)
doesn't seem to help, and using as.factor(year)
generates steps insteads of dots.

Help will be most appreciated.  I have listed the code
I have been using below:
> plot(y$year, y$V, type = "b")
> plot(as.character(y$year), y$V, type = "b")
> plot(as.character(y$year), y$V, type = "b")

Thanks,
NR

try text(c("1970", "1978", "1990"), x=1:3, y=1:3)
after you first
call plot(c(1, 3), c(1, 3), axes=F, type="n", xlab="",
ylab="")
to set the plotting area.

Yuelin.


--  From: Nirmala Ravishankar <n_ravishankar at yahoo.com>
  To: r-help at stat.math.ethz.ch
  Subject: [R] plot()
  Date: Mon, 6 Jan 2003 20:19:58 -0800 (PST)
  
  I am an R novice trying to figure out plot(). 
  Specifically, I am trying to plot the values of a
  numeric variable V for a set of years (1970, 1974,
  1976, 1978, 1980).  How do I get R to label the years
  I am plotting on the x-axis rather then some general
  levels (1970, 1975, 1980.)  Using as.character(year)
  doesn't seem to help, and using as.factor(year)
  generates steps insteads of dots.
  
  Help will be most appreciated.  I have listed the code
  I have been using below:
  
  > plot(y$year, y$V, type = "b")
  > plot(as.character(y$year), y$V, type = "b")
  > plot(as.character(y$year), y$V, type = "b")
  
  
  Thanks,
  NR
  
  ______________________________________________
  R-help at stat.math.ethz.ch mailing list
  http://www.stat.math.ethz.ch/mailman/listinfo/r-help

First, it is usual to make plots with generic scales rather than label
each of the x values used, especially when they are irregularly spaced (as
here).  But if you want to do that, use axis() to create your own axis.
Here's a test

y <- data.frame(year=c(1970, 1974, 1976, 1978, 1980), V=rnorm(5))
attach(y)
plot(year, V, type = "b", xaxt="n")
axis(1, year, year)
detach()



On Mon, 6 Jan 2003, Nirmala Ravishankar wrote:
> I am an R novice trying to figure out plot().
> Specifically, I am trying to plot the values of a
> numeric variable V for a set of years (1970, 1974,
> 1976, 1978, 1980).  How do I get R to label the years
> I am plotting on the x-axis rather then some general
> levels (1970, 1975, 1980.)  Using as.character(year)
> doesn't seem to help, and using as.factor(year)
> generates steps insteads of dots.
>
> Help will be most appreciated.  I have listed the code
> I have been using below:
>
> > plot(y$year, y$V, type = "b")
> > plot(as.character(y$year), y$V, type = "b")
> > plot(as.character(y$year), y$V, type = "b")
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595