| # File src/library/graphics/R/grid.R |
| # Part of the R package, https://www.R-project.org |
| # |
| # Copyright (C) 1995-2012 The R Core Team |
| # |
| # This program is free software; you can redistribute it and/or modify |
| # it under the terms of the GNU General Public License as published by |
| # the Free Software Foundation; either version 2 of the License, or |
| # (at your option) any later version. |
| # |
| # This program is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| # GNU General Public License for more details. |
| # |
| # A copy of the GNU General Public License is available at |
| # https://www.R-project.org/Licenses/ |
| |
| grid <- function (nx = NULL, ny = nx, col="lightgray", lty="dotted", |
| lwd = par("lwd"), equilogs = TRUE) |
| { |
| if(is.null(nx) || (!is.na(nx) && nx >= 1)) { |
| log <- par("xlog") |
| if(is.null(nx)) { ## align to tickmarks |
| ax <- par("xaxp") |
| if(log && equilogs && ax[3L] > 0) ax[3L] <- 1 |
| at <- axTicks(1, axp = ax, log=log) |
| } else { # equidistant, also from box borders |
| U <- par("usr") |
| at <- seq.int(U[1L],U[2L], length.out = nx+1) |
| at <- (if(log) 10^at else at)[-c(1,nx+1)] |
| } |
| abline(v = at, col = col, lty = lty, lwd = lwd) |
| } |
| if(is.null(ny) || (!is.na(ny) && ny >= 1)) { |
| log <- par("ylog") |
| if(is.null(ny)) { ## align to tickmarks |
| ax <- par("yaxp") |
| if(log && equilogs && ax[3L] > 0) ax[3L] <- 1 |
| at <- axTicks(2, axp = ax, log=log) |
| } else { # equidistant, also from box borders |
| U <- par("usr") |
| at <- seq.int(U[3L],U[4L], length.out = ny+1) |
| at <- (if(log) 10^at else at)[-c(1,ny+1)] |
| } |
| abline(h = at, col = col, lty = lty, lwd = lwd) |
| } |
| } |