R help - Apr 2008 - Plotting with exact axis limits

Hello,

If I make a plot, say something simple like

plot( runif(100) )

then the origin (0,0) is not at the bottom-left corner of the box
surrounding the plot. The axis limits are "padded" slightly. This is
ordinarily a good feature, because it makes plots look better. But now I
would like to make a plot with the origin exactly on the bottom left.
Through trial and error, I have discovered that this padding is
approximately 3.8% of the axis length. That is,

plot( runif(100), ylim=c(.038,1), xlim=c(3.8,100))

gives the desired result. However, this seems like a rather inelegant hack.
Is there a "correct" way to do this?

Thank you!
Enrico

	[[alternative HTML version deleted]]

On 14/04/2008 6:56 PM, Enrico Rossi wrote:
> Hello,
> 
> If I make a plot, say something simple like
> 
> plot( runif(100) )
> 
> then the origin (0,0) is not at the bottom-left corner of the box
> surrounding the plot. The axis limits are "padded" slightly. This
is
> ordinarily a good feature, because it makes plots look better. But now I
> would like to make a plot with the origin exactly on the bottom left.
> Through trial and error, I have discovered that this padding is
> approximately 3.8% of the axis length. That is,
> 
> plot( runif(100), ylim=c(.038,1), xlim=c(3.8,100))
> 
> gives the desired result. However, this seems like a rather inelegant hack.
> Is there a "correct" way to do this?
plot(runif(100), yaxs='i', xaxs='i', ylim=c(0,1), xlim=c(0,
100))

is the "correct" way.  yaxs and xaxs are documented in ?par.

The only problem with this is that it may be too tight at the upper 
limits, because you can't ask to expand at the top but not at the bottom.

Duncan Murdoch

Hi,

type ?plot [Enter]and click the "par" link in the first line. This
takes you
to all the parameters you can set for plot commands. The one you are looking
for is:

xaxs

The style of axis interval calculation to be used for the x-axis. Possible
values are "r", "i", "e", "s",
"d". The styles are generally controlled by
the range of data or xlim, if given. Style "r" (regular) first extends
the
data range by 4 percent and then finds an axis with pretty labels that fits
within the range. Style "i" (internal) just finds an axis with pretty
labels
that fits within the original data range. Style "s" (standard) finds
an axis
with pretty labels within which the original data range fits. Style
"e"
(extended) is like style "s", except that it is also ensures that
there is
room for plotting symbols within the bounding box. Style "d" (direct)
specifies that the current axis should be used on subsequent plots. (Only
"r" and "i" styles are currently implemented) 

Cheers,
Daniel


-------------------------
cuncta stricte discussurus
-------------------------

-----Urspr?ngliche Nachricht-----
Von: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] Im
Auftrag von Enrico Rossi
Gesendet: Monday, April 14, 2008 6:57 PM
An: r-help at r-project.org
Betreff: [R] Plotting with exact axis limits

Hello,

If I make a plot, say something simple like

plot( runif(100) )

then the origin (0,0) is not at the bottom-left corner of the box
surrounding the plot. The axis limits are "padded" slightly. This is
ordinarily a good feature, because it makes plots look better. But now I
would like to make a plot with the origin exactly on the bottom left.
Through trial and error, I have discovered that this padding is
approximately 3.8% of the axis length. That is,

plot( runif(100), ylim=c(.038,1), xlim=c(3.8,100))

gives the desired result. However, this seems like a rather inelegant hack.
Is there a "correct" way to do this?

Thank you!
Enrico

	[[alternative HTML version deleted]]

______________________________________________
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.