Don't try to make a graph with one line (it will fail), and don't mark analysis as failed if graph isn't made for that reason

2 files changed, 3 insertions, 3 deletions

diff --git a/cmd/bookpipeline/main.go b/cmd/bookpipeline/main.go
index f7c2ae9..6687329 100644
--- a/cmd/bookpipeline/main.go
+++ b/cmd/bookpipeline/main.go
@@ -373,7 +373,7 @@ func analyse(conn Pipeliner) func(chan string, chan string, chan error, *log.Log
 	}
 	defer f.Close()
 	err = bookpipeline.Graph(bestconfs, filepath.Base(savedir), f)
-	if err != nil {
+	if err != nil && err.Error() != "Not enough valid confidences" {
 		close(up)
 		errc <- errors.New(fmt.Sprintf("Error rendering graph: %s", err))
 		return
diff --git a/graph.go b/graph.go
index c56ba48..4ca44a7 100644
--- a/graph.go
+++ b/graph.go
@@ -51,8 +51,8 @@ func Graph(confs map[string]*Conf, bookname string, w io.Writer) error {
 }
 
 func GraphOpts(confs map[string]*Conf, bookname string, xaxis string, guidelines bool, w io.Writer) error {
-	if len(confs) == 0 {
-		return errors.New("No valid confidences")
+	if len(confs) < 2 {
+		return errors.New("Not enough valid confidences")
 	}
 
 	// Organise confs to sort them by page