fix tanh func, typo

Mrezadwiprasetiawan · web-flow · commit 1e2389402073 · 2025-05-06T20:53:24.000+07:00
diff --git a/NN/FFN/basicFFN/include/ffn.hxx b/NN/FFN/basicFFN/include/ffn.hxx
@@ -72,7 +72,7 @@ class FFN {
   static FP sigmoid(FP x) { return 1 / (1 + std::exp(-x)); }
   static FP sigmoid_deriv(FP y) { return y * (1 - y); }
   static FP tanh(FP x) {
-    return (std::exp(x) - std::exp(-x)) / (std::exp(x) - std::exp(-x));
+    return (std::exp(x) - std::exp(-x)) / (std::exp(x) + std::exp(-x));
   }
   static FP tanh_deriv(FP y) { return 1 - y * y; }
 

Original file line number	Diff line number	Diff line change
`@@ -72,7 +72,7 @@ class FFN {`
`72`	`72`	`static FP sigmoid(FP x) { return 1 / (1 + std::exp(-x)); }`
`73`	`73`	`static FP sigmoid_deriv(FP y) { return y * (1 - y); }`
`74`	`74`	`static FP tanh(FP x) {`
`75`		`- return (std::exp(x) - std::exp(-x)) / (std::exp(x) - std::exp(-x));`
	`75`	`+ return (std::exp(x) - std::exp(-x)) / (std::exp(x) + std::exp(-x));`
`76`	`76`	`}`
`77`	`77`	`static FP tanh_deriv(FP y) { return 1 - y * y; }`
`78`	`78`