From 503a54f408d631a9668b8a61f3e274cad64f1220 Mon Sep 17 00:00:00 2001
From: Michael Friendly <friendly@yorku.ca>
Date: Sat, 19 Oct 2024 21:56:13 -0400
Subject: [PATCH] plotEqn() gains a ... arg

---
 R/plotEqn.R        | 10 ++++++----
 dev/plotEqn-test.R |  6 +++---
 man/plotEqn.Rd     |  5 ++++-
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/R/plotEqn.R b/R/plotEqn.R
index 35b77e4e..2ee5e562 100644
--- a/R/plotEqn.R
+++ b/R/plotEqn.R
@@ -21,6 +21,7 @@
 #'      using the character string resulting from \code{\link{showEqn}}, modified so that the
 #'      \code{x}s are properly subscripted.
 #' @param solution logical; should the solution points for pairs of equations be marked?
+#' @param ... Other arguments passed to \code{plot}
 #' @return nothing; used for the side effect of making a plot
 #'
 #' @author Michael Friendly
@@ -45,9 +46,10 @@
 plotEqn <- function(A, b, vars, xlim, ylim,
                     col=1:nrow(A), lwd=2, lty=1,
                     axes=TRUE, labels=TRUE,
-                    solution=TRUE
+                    solution=TRUE,
+                    ...
 ) {
-
+  
   if (!is.numeric(A) || !is.matrix(A)) stop("A must be a numeric matrix")
   if (missing(b)) {
     b <- A[ , ncol(A)]   # assume last column of Ab
@@ -114,8 +116,8 @@ plotEqn <- function(A, b, vars, xlim, ylim,
   }
 
   for (i in 1:neq) {
-    if (i == 1) plot(xlim, ylim, type="n", xlab = vars[1], ylab = vars[2], xlim = xlim, ylim = ylim)
-
+    if (i == 1) plot(xlim, ylim, type="n", xlab = vars[1], ylab = vars[2], xlim = xlim, ylim = ylim, ...)
+    
     if (A[i, 2] == 0) {
       abline(v = b[i] / A[i, 1], col = col[i], lwd = lwd[i], lty = lty[i])
       y <- ylim
diff --git a/dev/plotEqn-test.R b/dev/plotEqn-test.R
index 57d2bc5a..d1ae6ad4 100644
--- a/dev/plotEqn-test.R
+++ b/dev/plotEqn-test.R
@@ -2,6 +2,8 @@
 
 library(matlib)
 
+source(here::here("dev", "plotEqn.R"))
+
 A <- matrix(c( 1, 2, 0,
                -1, 2, 1), 3, 2) |>
   print()
@@ -11,9 +13,7 @@ b <- c(2, 1, 1)
 
 showEqn(A, b, vars = c("x", "y"), simplify = TRUE)
 
-plotEqn(A, b, vars = c("x", "y"),
-        cex.lab = 2,
-        solution = list(pch = 16))
+plotEqn(A, b, vars = c("x", "y"))
         
 # try to change the labels: doesn't work
 plotEqn(A, b, vars = c("x", "y"),
diff --git a/man/plotEqn.Rd b/man/plotEqn.Rd
index 9fa6ef48..944b8ff3 100644
--- a/man/plotEqn.Rd
+++ b/man/plotEqn.Rd
@@ -15,7 +15,8 @@ plotEqn(
   lty = 1,
   axes = TRUE,
   labels = TRUE,
-  solution = TRUE
+  solution = TRUE,
+  ...
 )
 }
 \arguments{
@@ -47,6 +48,8 @@ using the character string resulting from \code{\link{showEqn}}, modified so tha
 \code{x}s are properly subscripted.}
 
 \item{solution}{logical; should the solution points for pairs of equations be marked?}
+
+\item{...}{Other arguments passed to \code{plot}}
 }
 \value{
 nothing; used for the side effect of making a plot