Add documentation and very simple test for array atan(), part 2

(files I forget in the previous commit).

1 files changed, 2 insertions, 0 deletions

diff --git a/doc/snippets/Cwise_atan.cpp b/doc/snippets/Cwise_atan.cpp
new file mode 100644
index 000000000..446844726
--- /dev/null
+++ b/doc/snippets/Cwise_atan.cpp
@@ -0,0 +1,2 @@
+ArrayXd v = ArrayXd::LinSpaced(5,0,1);
+cout << v.atan() << endl;