diff --git a/doc/data/small.csv b/doc/data/small.csv
new file mode 100644
index 000000000..e60e6c64d
--- /dev/null
+++ b/doc/data/small.csv
@@ -0,0 +1,6 @@
+a,b,i,x,y
+pan,pan,1,0.3467901443380824,0.7268028627434533
+eks,pan,2,0.7586799647899636,0.5221511083334797
+wye,wye,3,0.20460330576630303,0.33831852551664776
+eks,wye,4,0.38139939387114097,0.13418874328430463
+wye,pan,5,0.5732889198020006,0.8636244699032729