def poisson(y_true, y_pred):
 return tf.reduce_sum((y_pred - (y_true * tf.log((y_pred + 1e-08)))))

def poisson ( y_true , y_pred ) : return tf . reduce_sum ( ( y_pred - ( y_true * tf . log ( ( y_pred + 1e-08 ) ) ) ) )
draw samples from a poisson distribution .