Squashed 'third_party/eigen/' changes from 61d72f6..cf794d3


Change-Id: I9b814151b01f49af6337a8605d0c42a3a1ed4c72
git-subtree-dir: third_party/eigen
git-subtree-split: cf794d3b741a6278df169e58461f8529f43bce5d
diff --git a/doc/snippets/Cwise_log10.cpp b/doc/snippets/Cwise_log10.cpp
new file mode 100644
index 0000000..b7ae4a8
--- /dev/null
+++ b/doc/snippets/Cwise_log10.cpp
@@ -0,0 +1,2 @@
+Array4d v(-1,0,1,2);
+cout << log10(v) << endl;