From 9e240266faeb08d3787d6c035d55b39073a9d5b9 Mon Sep 17 00:00:00 2001
From: Aashil Patel <aashilpatel1993@gmail.com>
Date: Sat, 18 Feb 2017 15:17:35 -0500
Subject: [PATCH] Explain the meaning of X_m in modules/tree doc.

---
 doc/modules/tree.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/doc/modules/tree.rst b/doc/modules/tree.rst
index d0d446906f4d9..f53069782fec9 100644
--- a/doc/modules/tree.rst
+++ b/doc/modules/tree.rst
@@ -480,6 +480,8 @@ and Misclassification
 
     H(X_m) = 1 - \max(p_{mk})
 
+where :math:`X_m` is the training data in node :math:`m`
+
 Regression criteria
 -------------------
 
@@ -493,6 +495,7 @@ criterion to minimise is the Mean Squared Error
 
     H(X_m) = \frac{1}{N_m} \sum_{i \in N_m} (y_i - c_m)^2
 
+where :math:`X_m` is the training data in node :math:`m`
 
 .. topic:: References: