| abline {graphics} | R Documentation |
This function adds one or more straight lines through the current plot.
abline(a, b, untf = FALSE, ...) abline(h=, untf = FALSE, ...) abline(v=, untf = FALSE, ...) abline(coef=, untf = FALSE, ...) abline(reg=, untf = FALSE, ...)
a, b |
the intercept and slope, single values. |
untf |
logical asking whether to untransform. See Details. |
h |
the y-value(s) for horizontal line(s). |
v |
the x-value(s) for vertical line(s). |
coef |
a vector of length two giving the intercept and slope. |
reg |
an object with a coef component. See Details. |
... |
graphical parameters such as col, lty and
lwd (possibly as vectors: see Details). |
The first form specifies the line in intercept/slope form
(alternatively a can be specified on its own and is taken to
contain the slope and intercept in vector form).
The h= and v= forms draw horizontal and vertical lines
at the specified coordinates.
The coef form specifies the line by a vector containing the
slope and intercept.
reg is a regression object which contains reg$coef. If
it is of length 1 then the value is taken to be the slope of a line
through the origin, otherwise, the first 2 values are taken to be the
intercept and slope.
If untf is true, and one or both axes are log-transformed, then
a curve is drawn corresponding to a line in original coordinates,
otherwise a line is drawn in the transformed coordinate system. The
h and v parameters always refer to original coordinates.
The graphical parameters col, lty and lwd
can be specified; see par for details. For the
h= and v= cases they can be vectors of length greater
than one, recycled as necessary.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
lines and segments for connected and
arbitrary lines given by their endpoints.
par.
z <- lm(dist ~ speed, data = cars) plot(cars) abline(z)