lambda cost bug's fix

7f0c8230 · chengxingyi · 78327c8e · 7f0c8230
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内联并排

Showing with 2 addition and 2 deletion

paddle/gserver/layers/CostLayer.cpp paddle/gserver/layers/CostLayer.cpp +2 -2

未找到文件。
--- a/paddle/gserver/layers/CostLayer.cpp
+++ b/paddle/gserver/layers/CostLayer.cpp
@@ -462,8 +462,8 @@ void LambdaCost::calcGrad(const real* outputScore,
      real score_j = score[index_j];
      real dcgDif = 0;
      if (j < sortSize) {
-        dcgDif = (std::pow(2, score_i) - std::pow(2, score_j)) /
+        dcgDif = (std::pow(2, score_i) - std::pow(2, score_j)) *
-                 (std::log(i + 2) - std::log(j + 2));
+                 (1 / std::log(i + 2) - 1 / std::log(j + 2));
      } else {
        dcgDif =
            (std::pow(2, score_i) - std::pow(2, score_j)) / std::log(i + 2);