Add zero loss

Author: lululxvi

deepxde/losses.py

@@ -2,6 +2,7 @@
 from __future__ import division
 from __future__ import print_function
 
+from . import config
 from .backend import tf
 
 
@@ -15,6 +16,10 @@ def mean_squared_error(y_true, y_pred):
     return tf.reduce_mean(tf.math.square(y_true - y_pred))
 
 
+def zero(*_):
+    return tf.constant(0, dtype=config.real(tf))
+
+
 mean_absolute_error = tf.keras.losses.MeanAbsoluteError()
 mean_absolute_percentage_error = tf.keras.losses.MeanAbsolutePercentageError()
 softmax_cross_entropy = tf.losses.softmax_cross_entropy
@@ -35,6 +40,7 @@ def get(identifier):
         "MAPE": mean_absolute_percentage_error,
         "mape": mean_absolute_percentage_error,
         "softmax cross entropy": softmax_cross_entropy,
+        "zero": zero,
     }
 
     if isinstance(identifier, str):