commit 2c873e1: [Fix] Change neural plugin's loss function

[Pragadeesh C]

Author: Pragadeesh C
Date: 2020-08-19 02:47:49 -0400
URL: https://github.com/rspamd/rspamd/commit/2c873e1d61925293b471f8b4cdb9d6b7d86fac8c (refs/pull/3478/head)

[Fix] Change neural plugin's loss function
Modified the neural network to use ceb_neg loss function.

---
 src/plugins/lua/neural.lua | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/plugins/lua/neural.lua b/src/plugins/lua/neural.lua
index e3518d3bd..99efe720e 100644
--- a/src/plugins/lua/neural.lua
+++ b/src/plugins/lua/neural.lua
@@ -342,8 +342,8 @@ local function create_ann(n, nlayers)
   local nhidden = math.floor((n + 1) / 2)
   local t = rspamd_kann.layer.input(n)
   t = rspamd_kann.transform.relu(t)
-  t = rspamd_kann.transform.tanh(rspamd_kann.layer.dense(t, nhidden));
-  t = rspamd_kann.layer.cost(t, 1, rspamd_kann.cost.mse)
+  t = rspamd_kann.layer.dense(t, nhidden);
+  t = rspamd_kann.layer.cost(t, 1, rspamd_kann.cost.ceb_neg)
   return rspamd_kann.new.kann(t)
 end