fix #140

Author: Christophe-Regouby

R/activation.R

@@ -5,7 +5,7 @@
 #' @param alpha (float) the weight of ELU activation component.
 #' @param beta (float) the weight of PReLU activation component.
 #' @param gamma (float) the weight of SiLU activation component.
-#' @param init (float): the initial value of \eqn{a} of PReLU. Default: 0.25.
+#' @param weight (torch_tensor): the initial value of \eqn{weight} of PReLU. Default: 0.25.
 #'
 #' @return an activation function computing
 #' \eqn{\mathbf{MBwLU(input) = \alpha \times ELU(input) + \beta \times PReLU(input) + \gamma \times SiLU(input)}}
@@ -20,14 +20,15 @@
 #' @export
 nn_mb_wlu <- torch::nn_module(
   "multibranch Weighted Linear Unit",
-  initialize = function(alpha = 0.6, beta = 0.2, gamma = 0.2, init = 0.25) {
+  initialize = function(alpha = 0.6, beta = 0.2, gamma = 0.2, weight = torch::torch_tensor(0.25)) {
+    stopifnot("weight must be a torch_tensor()" = inherits(weight, "torch_tensor"))
     self$alpha <- alpha
     self$beta <- beta
     self$gamma <- gamma
-    self$init <- init
+    self$weight <- weight
   },
   forward = function(input) {
-    nnf_mb_wlu(input, self$alpha, self$beta, self$gamma, self$init)
+    nnf_mb_wlu(input, self$alpha, self$beta, self$gamma, self$weight)
   }
 )
 
@@ -36,9 +37,10 @@ nn_mb_wlu <- torch::nn_module(
 #' @seealso [nn_mb_wlu()].
 #' @export
 #' @rdname nn_mb_wlu
-nnf_mb_wlu <- function(input, alpha = 0.6, beta = 0.2, gamma = 0.2,  init = 0.25) {
-    alpha * torch::nnf_elu(input) +
-      beta * torch::nnf_prelu(input, init) +
-      gamma * torch::nnf_silu(input)
+nnf_mb_wlu <- function(input, alpha = 0.6, beta = 0.2, gamma = 0.2,  weight = torch::torch_tensor(0.25)) {
+  stopifnot("weight and input must reside on the same device" = weight$device == input$device)
+  alpha * torch::nnf_elu(input) +
+    beta * torch::nnf_prelu(input, weight) +
+    gamma * torch::nnf_silu(input)
 
 }

R/model.R

@@ -256,12 +256,18 @@ interpretabnet_config <- function(mask_type = "entmax",
                                    mlp_hidden_multiplier = c(4,2),
                                    mlp_activation = NULL,
                                    encoder_activation = nn_mb_wlu(), ...) {
-  tabnet_config(mask_type = mask_type,
+  interpretabnet_conf <- tabnet_config(mask_type = mask_type,
                 mlp_hidden_multiplier = mlp_hidden_multiplier,
                 mlp_activation = mlp_activation,
                 encoder_activation = encoder_activation,
                 ...)
-
+  # align  nn_mb_wlu weight device with the config device
+  device <- get_device_from_config(interpretabnet_conf)
+  if (!grepl(device,interpretabnet_conf$encoder_activation$weight$device )) {
+    # move the weight to the config device
+    interpretabnet_conf$encoder_activation$weight <- interpretabnet_conf$encoder_activation$weight$to(device = device)
+  }
+  interpretabnet_conf
 }
 
 get_constr_output <- function(x, R) {

man/nn_mb_wlu.Rd

@@ -1,4 +1,4 @@
-test_that("multibranch_weighted_linear_unit nn_module works", {
+test_that("multibranch_weighted_linear_unit activation works", {
   mb_wlu <- nn_mb_wlu()
   input <- torch::torch_tensor(c(-1.0, 0.0, 1.0))
   expected_output <- torch::torch_tensor(c(-0.48306063, 0.0, 0.94621176))
@@ -7,3 +7,18 @@ test_that("multibranch_weighted_linear_unit nn_module works", {
 
 })
 
+test_that("multibranch_weighted_linear_unit correctly prevent weight not being a tensor", {
+  expect_error(mb_wlu <- nn_mb_wlu( weight = 0.25),
+               regexp = "must be a torch_tensor")
+})
+
+test_that("multibranch_weighted_linear_unit correctly prevent weight not being on the same device", {
+  skip_if_not(torch::backends_openmp_is_available())
+  weight <- torch::torch_tensor(0.25)$to(device = "cpu")
+  z <- torch::torch_randr(c(2,2))$to(device = "openmp")
+
+  expect_no_error(mb_wlu <- nn_mb_wlu( weight = weight))
+  expect_error(mb_wlu(z),
+               regexp = "reside on the same device")
+})
+