diff --git a/testdata.csv b/testdata.csv
new file mode 100644
index 0000000..2c97f8c
--- /dev/null
+++ b/testdata.csv
@@ -0,0 +1,8 @@
+data1,data2,
+1.0,1.1,
+1.1,1.2,
+0.9,1.3,
+1.0,1.4,
+1.0,1.5,
+0.9,1.6,
+0.9,1.7,