“ callback_tensorboard ...未使用的参数中的错误（embedddings_data = x_test）”

Question

我正在使用keras“ mnist_cnn_embeddings”示例中的确切代码，并且在使用tensorboard回调函数时遇到错误。

如果我注释掉embeddings_data参数，那么我将不再收到错误，但会收到警告，“缺少函数调用参数”

library(keras)

# Data Preparation -----------------------------------------------------

batch_size <- 128
num_classes <- 10
epochs <- 12

# Input image dimensions
img_rows <- 28
img_cols <- 28

# The data, shuffled and split between train and test sets
mnist <- dataset_mnist()
x_train <- mnist$train$x
y_train <- mnist$train$y
x_test <- mnist$test$x
y_test <- mnist$test$y

# Redefine  dimension of train/test inputs
x_train <-
  array_reshape(x_train, c(nrow(x_train), img_rows, img_cols, 1))
x_test <-
  array_reshape(x_test, c(nrow(x_test), img_rows, img_cols, 1))
input_shape <- c(img_rows, img_cols, 1)

# Transform RGB values into [0,1] range
x_train <- x_train / 255
x_test <- x_test / 255

cat('x_train_shape:', dim(x_train), '\n')
cat(nrow(x_train), 'train samples\n')
cat(nrow(x_test), 'test samples\n')


# Prepare for logging embeddings --------------------------------------------------

embeddings_dir <- file.path(tempdir(), 'embeddings')
if (!file.exists(embeddings_dir))
  dir.create(embeddings_dir)
embeddings_metadata <- file.path(embeddings_dir, 'metadata.tsv')

# we use the class names from the test set as embeddings_metadata
readr::write_tsv(data.frame(y_test), path = embeddings_metadata, col_names = FALSE)

tensorboard_callback <- callback_tensorboard(
    log_dir = embeddings_dir,
    batch_size = batch_size,
    embeddings_freq = 1,
    # if missing or NULL all embedding layers will be monitored
    embeddings_layer_names = list('features'),
    # single file for all embedding layers, could also be a named list mapping
    # layer names to file names
    embeddings_metadata = embeddings_metadata,
    #data to be embedded
    embeddings_data = x_test
)

错误：

Error in callback_tensorboard(log_dir = embeddings_dir, batch_size = batch_size,  : 
  unused argument (embeddings_data = x_test)