numerically stable softmax

DESCRIPTION

@@ -1,8 +1,8 @@
 Package: learningmachine
 Type: Package
 Title: Machine Learning with Explanations and Uncertainty Quantification
-Version: 2.7.1
-Date: 2024-11-11
+Version: 2.7.2
+Date: 2024-11-29
 Author: T. Moudiki
 Maintainer: T. Moudiki <[email protected]>
 Description: Regression-based Machine Learning with explanations and uncertainty quantification.
@@ -32,3 +32,4 @@ Suggests:
 Roxygen: list(markdown = TRUE)
 VignetteBuilder: knitr
 Config/testthat/edition: 3
+Remotes: thierrymoudiki/bayesianrvfl

R/utils_all.R

@@ -53,7 +53,7 @@ create_new_predictors <- function(x, nb_hidden = 5,
   }
   g <- switch(match.arg(activ),
               "relu" = function(x) x*(x>0),
-              "sigmoid" = function(x) 1/(1 + exp(-x)),
+              "sigmoid" = function(x) (1/(1 + exp(-x)))*(x >= 0) + (exp(x)/(1 + exp(x)))*(x < 0),
               "tanh" = function(x) tanh(x),
               "leakyrelu" = function(x) x*(x > 0) + 0.01*x*(x <= 0),
               "elu" = function(x) x*(x >= 0) + 0.01*(exp(x)-1)*(x < 0),
@@ -205,7 +205,8 @@ get_classes_idx <- function(new_probs, q_threshold, level) {
 
 # get expit probs -----
 expit_probs <- function(x) {
-  temp <- 1 / (1 + exp(-x))
+  temp <- (1 / (1 + exp(-x)))*(x >= 0)
+  temp <- temp + (exp(x)/(1 + exp(x)))*(x < 0)  
   return(sweep(x=temp, MARGIN=1, FUN="/", 
                STATS=rowSums(temp)))
 }

R/zzz.R

@@ -0,0 +1,8 @@
+.onLoad <- function(libname, pkgname){
+    if (!requireNamespace("devtools", quietly = TRUE)) {
+      utils::install.packages("devtools")
+    }
+    if (!requireNamespace("bayesianrvfl", quietly = TRUE)) {
+    devtools::install_github("thierrymoudiki/bayesianrvfl")
+    }
+}