adding more stringent defenses to the plottinng fn

diff --git a/plottingTools.R b/plottingTools.R
index 6766e99..c7411bb 100644
--- a/plottingTools.R
+++ b/plottingTools.R
@@ -7,15 +7,32 @@

 # function to generate a semi-log plot of two vectors with connecting lines
 plotMC <- function(NS,probs, wHist=T) {
-	# obtain lenght of vectors
+	# DEFENSE ... DEFENSE ...
+	# this internal fn takes care of protecting the fn for receiving the proper arguments
+	defense <- function(input1,input2) {
+		# check that the arguments are vectors, ie. not a list!
+		if ( (class(input1) == "list") | (class(input2) == "list") ) {
+			stop("The fn requires two numeric vectors!")
+		}
+
+		# check that the arguments are numbers!
+		if ( !is.numeric(input1) | !is.numeric(input2) ) {
+			stop("The fn requires two numeric vectors!")
+		}
+
+		# check that the arguments have matching dimensions
+		if (length(input1) != length(input2)) {
+			stop("This function requires two vectors with the same number of elements!")
+		}
+	}
+
+	# execute defensive programming first!
+	defense(NS,probs)
+
+	# obtain lenght of vectors
 	lNS <- length(NS)
 	lprobs <- length(probs)

-	# check that the arguments have matching dimensions
-	if (lNS != lprobs) {
-		stop("This function requires two vectors with the same number of elements!")
-	}
-
 	# set up figure canvas
 	par(fig = c(0,1,0,1))