allow user to override plot limits

1 files changed, 15 insertions, 7 deletions

diff --git a/R/plot.gensvm.R b/R/plot.gensvm.R
index 85ff3b5..cbad9f0 100644
--- a/R/plot.gensvm.R
+++ b/R/plot.gensvm.R
@@ -15,6 +15,11 @@
 #' @param with.legend show the legend for the class labels
 #' @param center.plot ensure that the boundaries and margins are always visible 
 #' in the plot
+#' @param xlim allows the user to force certain plot limits. If set, these 
+#' bounds will be used for the horizontal axis.
+#' @param ylim allows the user to force certain plot limits. If set, these 
+#' bounds will be used for the vertical axis and the value of center.plot will 
+#' be ignored
 #' @param ... further arguments are ignored
 #'
 #' @return returns the object passed as input
@@ -52,7 +57,7 @@
 #'
 plot.gensvm <- function(fit, x, y.true=NULL, with.margins=TRUE, 
                         with.shading=TRUE, with.legend=TRUE, center.plot=TRUE,
-                        ...)
+                        xlim=NULL, ylim=NULL, ...)
 {
     if (fit$n.classes != 3) {
         cat("Error: Can only plot with 3 classes\n")
@@ -74,7 +79,8 @@ plot.gensvm <- function(fit, x, y.true=NULL, with.margins=TRUE,
         return
     }
     if (!is.null(x.train) && ncol(x.train) != fit$n.features) {
-        cat("Error: Number of features of fitted model and training data disagree.")
+        cat("Error: Number of features of fitted model and training data ",
+            "disagree.\n", sep="")
         return
     }
 
@@ -136,13 +142,15 @@ plot.gensvm <- function(fit, x, y.true=NULL, with.margins=TRUE,
 
     par(pty="s")
     if (center.plot) {
-        new.xlim <- c(min(min(S[, 1]), -1.2), max(max(S[, 1]), 1.2))
-        new.ylim <- c(min(min(S[, 2]), -0.75), max(max(S[, 2]), 1.2))
+        if (is.null(xlim))
+            xlim <- c(min(min(S[, 1]), -1.2), max(max(S[, 1]), 1.2))
+        if (is.null(ylim))
+            ylim <- c(min(min(S[, 2]), -0.75), max(max(S[, 2]), 1.2))
         plot(S[, 1], S[, 2], col=col.vector, pch=mark.vector, ylab='', xlab='', 
-             asp=1, xlim=new.xlim, ylim=new.ylim)
+             asp=1, xlim=xlim, ylim=ylim)
     } else {
-        plot(S[, 1], S[, 2], col=col.vector, pch=mark.vector, ylab='', xlab='', 
-             asp=1)
+        plot(S[, 1], S[, 2], col=col.vector, pch=mark.vector, ylab='', 
+             xlab='', asp=1, xlim=xlim, ylim=ylim)
     }
 
     limits <- par("usr")