Merge "Add method to encode probability."

2 files changed, 38 insertions, 0 deletions

diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/probability_utils.cpp b/native/jni/src/suggest/policyimpl/dictionary/utils/probability_utils.cpp
new file mode 100644
index 000000000..e8fa06942
--- /dev/null
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/probability_utils.cpp
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2014, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "suggest/policyimpl/dictionary/utils/probability_utils.h"
+
+namespace latinime {
+
+const float ProbabilityUtils::PROBABILITY_ENCODING_SCALER = 8.58923700372f;
+
+} // namespace latinime
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/probability_utils.h b/native/jni/src/suggest/policyimpl/dictionary/utils/probability_utils.h
index 3b339e61a..2050af1e9 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/probability_utils.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/probability_utils.h
@@ -17,6 +17,9 @@
 #ifndef LATINIME_PROBABILITY_UTILS_H
 #define LATINIME_PROBABILITY_UTILS_H
 
+#include <algorithm>
+#include <cmath>
+
 #include "defines.h"
 
 namespace latinime {
@@ -47,8 +50,20 @@ class ProbabilityUtils {
                 + static_cast<int>(static_cast<float>(bigramProbability + 1) * stepSize);
     }
 
+    // Encode probability using the same way as we are doing for main dictionaries.
+    static AK_FORCE_INLINE int encodeRawProbability(const float rawProbability) {
+        const float probability = static_cast<float>(MAX_PROBABILITY)
+                + log2f(rawProbability) * PROBABILITY_ENCODING_SCALER;
+        if (probability < 0.0f) {
+            return 0;
+        }
+        return std::min(static_cast<int>(probability + 0.5f), MAX_PROBABILITY);
+    }
+
  private:
     DISALLOW_IMPLICIT_CONSTRUCTORS(ProbabilityUtils);
+
+    static const float PROBABILITY_ENCODING_SCALER;
 };
 }
 #endif /* LATINIME_PROBABILITY_UTILS_H */