Add code snippets for new methods
diff --git a/doc/snippets/Cwise_ceil.cpp b/doc/snippets/Cwise_ceil.cpp
new file mode 100644
index 0000000..76cf661
--- /dev/null
+++ b/doc/snippets/Cwise_ceil.cpp
@@ -0,0 +1,3 @@
+ArrayXd v = ArrayXd::LinSpaced(7,-2,2);
+cout << v << endl << endl;
+cout << ceil(v) << endl;