tests/marshal.keras.R

In HenrikBengtsson/marshal: Framework to Marshal Objects to be Used in Another R Process

library(marshal)

## WORKAROUND: tensorflow::tf_config() triggers the 'reticulate' package
## to create temporary folders under the 'TMPDIR' folder, not tempdir(),
## which then R CMD check --as-cran will complain about.
otd <- Sys.getenv("TMPDIR", NA_character_)
Sys.setenv(TMPDIR = tempdir())

if (requireNamespace("tensorflow", quietly = TRUE) && tensorflow::tf_config()$available && requireNamespace("keras", quietly = TRUE)) {
  library(keras)

  ## Create a keras model (adopted from {keras} vignette)
  inputs <- layer_input(shape = shape(32))
  
  outputs <- layer_dense(inputs, units = 1L)
  model <- keras_model(inputs, outputs)
  model <- compile(model, optimizer = "adam", loss = "mean_squared_error")
  print(model)

  ## Not needed anymore
  rm(list = c("inputs", "outputs"))

  ## Assert marshallability
  stopifnot(marshallable(model))

  ## Marshal
  model_ <- marshal(model)
  
  ## Unmarshal
  model2 <- unmarshal(model_)
  
  stopifnot(
    identical(summary(model2), summary(model))
  )


  ## Fitted keras model (adopted from {keras} vignette)
  test_input <- array(runif(128 * 32), dim = c(128, 32))
  test_target <- array(runif(128), dim = c(128, 1))

  ## Note: This writes several files to temporary directory
  hist <- fit(model, test_input, test_target)
  print(hist)
  print(model)
  
  ## Not needed anymore
  rm(list = "test_target")
  
  ## Marshal
  model_ <- marshal(model)
  
  ## Unmarshal
  model2 <- unmarshal(model_)
  
  stopifnot(
    identical(summary(model2), summary(model)),
    identical(stats::predict(model2, test_input), stats::predict(model, test_input))
  )
}

if (is.na(otd)) Sys.unsetenv("TMPDIR") else Sys.setenv(TMPDIR = otd)