From ab4147b484f973d6320e6fc95f7de9bff35c570e Mon Sep 17 00:00:00 2001
From: Titus von der Malsburg <malsburg@posteo.de>
Date: Tue, 25 Aug 2015 12:58:29 +0200
Subject: [PATCH] Fixed a bug in prepare.data which prevented the plotting
 function to fail in some situations.

---
 scanpath/R/scanpath.R | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/scanpath/R/scanpath.R b/scanpath/R/scanpath.R
index ba54c01..7c94206 100644
--- a/scanpath/R/scanpath.R
+++ b/scanpath/R/scanpath.R
@@ -262,9 +262,12 @@ avg.group.dist <- function(d, groups) {
 prepare.data <- function(data, formula)
 {
   terms <- strsplit(deparse(formula), " [~+|] ")[[1]]
-  stopifnot(length(terms)==4)
+  stopifnot(length(terms) %in% 3:4)
   df <- data[terms]
-  colnames(df) <- c("d", "x", "y", "trial")
+  if (length(terms)==3) 
+    colnames(df) <- c("d", "x", "trial")
+  else
+    colnames(df) <- c("d", "x", "y", "trial")
   df
 }