Add sequence error result to edit distance evaluator

Author: wanghaoshuang

python/paddle/v2/fluid/evaluator.py

@@ -243,25 +243,42 @@ def __init__(self, input, label, ignored_tokens=None, **kwargs):
         if main_program.current_block().idx != 0:
             raise ValueError("You can only invoke Evaluator in root block")
 
-        self.total_error = self.create_state(
-            dtype='float32', shape=[1], suffix='total_error')
+        self.total_distance = self.create_state(
+            dtype='float32', shape=[1], suffix='total_distance')
         self.seq_num = self.create_state(
             dtype='int64', shape=[1], suffix='seq_num')
-        error, seq_num = layers.edit_distance(
+        self.seq_error = self.create_state(
+            dtype='int64', shape=[1], suffix='seq_error')
+        distances, seq_num = layers.edit_distance(
             input=input, label=label, ignored_tokens=ignored_tokens)
+
+        zero = layers.fill_constant(shape=[1], value=0.0, dtype='float32')
+        compare_result = layers.equal(distances, zero)
+        compare_result_int = layers.cast(x=compare_result, dtype='int')
+        seq_right_count = layers.reduce_sum(compare_result_int)
+        seq_error_count = layers.elementwise_sub(x=seq_num, y=seq_right_count)
         #error = layers.cast(x=error, dtype='float32')
-        sum_error = layers.reduce_sum(error)
-        layers.sums(input=[self.total_error, sum_error], out=self.total_error)
+        total_distance = layers.reduce_sum(distances)
+        layers.sums(
+            input=[self.total_distance, total_distance],
+            out=self.total_distance)
         layers.sums(input=[self.seq_num, seq_num], out=self.seq_num)
-        self.metrics.append(sum_error)
+        layers.sums(input=[self.seq_error, seq_error_count], out=self.seq_error)
+        self.metrics.append(total_distance)
+        self.metrics.append(seq_error_count)
 
     def eval(self, executor, eval_program=None):
         if eval_program is None:
             eval_program = Program()
         block = eval_program.current_block()
         with program_guard(main_program=eval_program):
-            total_error = _clone_var_(block, self.total_error)
+            total_distance = _clone_var_(block, self.total_distance)
             seq_num = _clone_var_(block, self.seq_num)
+            seq_error = _clone_var_(block, self.seq_error)
             seq_num = layers.cast(x=seq_num, dtype='float32')
-            out = layers.elementwise_div(x=total_error, y=seq_num)
-        return np.array(executor.run(eval_program, fetch_list=[out])[0])
+            seq_error = layers.cast(x=seq_error, dtype='float32')
+            avg_distance = layers.elementwise_div(x=total_distance, y=seq_num)
+            avg_seq_error = layers.elementwise_div(x=seq_error, y=seq_num)
+            result = executor.run(eval_program,
+                                  fetch_list=[avg_distance, avg_seq_error])
+        return np.array(result[0]), np.array(result[1])