diff --git a/samples/spline.m b/samples/spline.m
new file mode 100644
index 0000000..d943046
--- /dev/null
+++ b/samples/spline.m
@@ -0,0 +1,15 @@
+x=[-2 0 2 3 4 5];
+y=[4 0 -4 -30 -40 -30];
+plot(x,y,'sr')
+hold on
+p=polyfit(x,y,5)
+
+p =
+
+   -0.2286    2.5333   -6.2286  -10.1333   26.5714    0.0000
+
+xx=-2:0.1:5;
+yy=polyval(p,xx);
+plot(xx,yy,'b')
+ys=spline(x,y,xx);
+plot(xx,ys,'g')