| # File src/library/graphics/R/abline.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/ |
| |
| abline <- function(a = NULL, b = NULL, h = NULL, v = NULL, reg = NULL, |
| coef = NULL, untf = FALSE, ...) |
| { |
| int_abline <- function(a, b, h, v, untf, col = par("col"), |
| lty = par("lty"), lwd = par("lwd"), ...) |
| .External.graphics(C_abline, a, b, h, v, untf, col, lty, lwd, ...) |
| |
| if(!is.null(reg)) { |
| if(!is.null(a)) warning("'a' is overridden by 'reg'") |
| a <- reg |
| } |
| if(is.object(a) || is.list(a)) { |
| ## was (!is.null(a) && is.list(a)) |
| p <- length(coefa <- as.vector(coef(a))) |
| if (p > 2) |
| warning(gettextf("only using the first two of %d regression coefficients", p), domain = NA) |
| islm <- inherits(a, "lm") |
| noInt <- if(islm) !as.logical(attr(stats::terms(a), "intercept")) else p == 1 |
| if (noInt) { |
| a <- 0 |
| b <- coefa[1L] |
| } else { |
| a <- coefa[1L] |
| b <- if (p >= 2) coefa[2L] else 0 |
| } |
| } |
| if(!is.null(coef)) { |
| if(!is.null(a)) warning("'a' and 'b' are overridden by 'coef'") |
| a <- coef[1L] |
| b <- coef[2L] |
| } |
| int_abline(a=a, b=b, h=h, v=v, untf=untf, ...) |
| invisible() |
| } |