| % File src/library/graphics/man/grid.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{grid} |
| \alias{grid} |
| \title{Add Grid to a Plot} |
| \description{ |
| \code{grid} adds an \code{nx} by \code{ny} rectangular grid to an |
| existing plot. |
| } |
| \usage{ |
| grid(nx = NULL, ny = nx, col = "lightgray", lty = "dotted", |
| lwd = par("lwd"), equilogs = TRUE) |
| } |
| \arguments{ |
| \item{nx, ny}{number of cells of the grid in x and y direction. When |
| \code{NULL}, as per default, the grid aligns with the tick marks on |
| the corresponding \emph{default} axis (i.e., tickmarks as computed by |
| \code{\link{axTicks}}). When \code{\link{NA}}, no grid lines are |
| drawn in the corresponding direction.} |
| \item{col}{character or (integer) numeric; color of the grid lines.} |
| \item{lty}{character or (integer) numeric; line type of the grid lines.} |
| \item{lwd}{non-negative numeric giving line width of the grid lines.} |
| \item{equilogs}{logical, only used when \emph{log} coordinates and |
| alignment with the axis tick marks are active. Setting \code{equilogs = |
| FALSE} in that case gives \emph{non equidistant} tick aligned |
| grid lines.} |
| } |
| \note{ |
| If more fine tuning is required, use \code{\link{abline}(h = ., v = .)} |
| directly. |
| } |
| \seealso{ |
| \code{\link{plot}}, \code{\link{abline}}, \code{\link{lines}}, |
| \code{\link{points}}. |
| } |
| \references{ |
| Murrell, P. (2005) \emph{R Graphics}. Chapman & Hall/CRC Press. |
| } |
| \examples{ |
| plot(1:3) |
| grid(NA, 5, lwd = 2) # grid only in y-direction |
| |
| ## maybe change the desired number of tick marks: par(lab = c(mx, my, 7)) |
| op <- par(mfcol = 1:2) |
| with(iris, |
| { |
| plot(Sepal.Length, Sepal.Width, col = as.integer(Species), |
| xlim = c(4, 8), ylim = c(2, 4.5), panel.first = grid(), |
| main = "with(iris, plot(...., panel.first = grid(), ..) )") |
| plot(Sepal.Length, Sepal.Width, col = as.integer(Species), |
| panel.first = grid(3, lty = 1, lwd = 2), |
| main = "... panel.first = grid(3, lty = 1, lwd = 2), ..") |
| } |
| ) |
| par(op) |
| |
| } |
| \keyword{aplot} |