Update losses_utils.cs

修改sample_weight初始化

src/TensorFlowNET.Keras/Utils/losses_utils.cs

@@ -1,4 +1,4 @@
-/*****************************************************************************
+/*****************************************************************************
    Copyright 2018 The TensorFlow.NET Authors. All Rights Reserved.
 
    Licensed under the Apache License, Version 2.0 (the "License");
@@ -25,7 +25,7 @@ namespace Tensorflow.Keras.Utils
         public static Tensor compute_weighted_loss(Tensor losses, Tensor sample_weight = null, string reduction = null, string name = null)
         {
             if (sample_weight == null)
-                sample_weight = tf.constant(1.0f);
+                sample_weight = losses.dtype.ToString()=="TF_DOUBLE"? tf.constant(1.0) : tf.constant(1.0f);
             var weighted_losses = scale_losses_by_sample_weight(losses, sample_weight);
             // Apply reduction function to the individual weighted losses.
             var loss = reduce_weighted_loss(weighted_losses, reduction);