add const for functions predict and score

qbarthelemy · Apr 7, 2022 · 6dbf50a · 6dbf50a
1 parent df77f02
commit 6dbf50a
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Showing 3 changed files with 8 additions and 10 deletions.
diff --git a/include/CSimpleLinearRegression.hpp b/include/CSimpleLinearRegression.hpp
@@ -68,7 +68,7 @@ class SimpleLinearRegression
 	* whose data type is double to keep the maximum of numerical precision.
 	*/
 	template<template<typename, typename> class ContType, typename ValType, typename Alloc>
-	ContType<double, std::allocator<double>> predict(const ContType<ValType, Alloc>& x)
+	ContType<double, std::allocator<double>> predict(const ContType<ValType, Alloc>& x) const
 	{
 		auto x_it = x.begin();
 		ContType<double, std::allocator<double>> y(x.size());
@@ -91,7 +91,7 @@ class SimpleLinearRegression
 	* @return R² of `predict(x)` wrt. `y`.
 	*/
 	template<template<typename, typename> class ContType, typename ValType, typename Alloc>
-	double score(const ContType<ValType, Alloc>& x, const ContType<ValType, Alloc>& y)
+	double score(const ContType<ValType, Alloc>& x, const ContType<ValType, Alloc>& y) const
 	{
 		size_t size = x.size();
 		if (size != y.size())

diff --git a/include/CSimpleLogisticRegression.hpp b/include/CSimpleLogisticRegression.hpp
@@ -100,11 +100,11 @@ class SimpleLogisticRegression
 	* whose data type is int to provide a binary target value.
 	*/
 	template<template<typename, typename> class ContType, typename ValType, typename Alloc>
-	ContType<int, std::allocator<int>> predict(const ContType<ValType, Alloc>& x)
+	ContType<int, std::allocator<int>> predict(const ContType<ValType, Alloc>& x) const
 	{
 		ContType<double, std::allocator<double>> y_lin = Maths::linear(x, get_coeff(), get_intercept());
 		ContType<double, std::allocator<double>> y_sig = Maths::sigmoid(y_lin);
-		
+
 		ContType<int, std::allocator<int>> y(x.size());
 		std::transform(y_sig.begin(), y_sig.end(), y.begin(), [](double e) { return e >= 0.5 ? 1 : 0; });
 
@@ -123,7 +123,7 @@ class SimpleLogisticRegression
 	* @return Accuracy of `predict(x)` wrt. `y`.
 	*/
 	template<template<typename, typename> class ContType, typename ValType, typename Alloc>
-	double score(const ContType<ValType, Alloc>& x, const ContType<int, std::allocator<int>>& y)
+	double score(const ContType<ValType, Alloc>& x, const ContType<int, std::allocator<int>>& y) const
 	{
 		ContType<int, std::allocator<int>> y_predict = predict(x);
 		return Stats::accuracy_score(y, y_predict);

diff --git a/include/Stats.hpp b/include/Stats.hpp
@@ -389,13 +389,11 @@ namespace Stats
 
 		double sxx = std::inner_product(x_cent.begin(), x_cent.end(), x_cent.begin(), 0.0);
 		double syy = std::inner_product(y_cent.begin(), y_cent.end(), y_cent.begin(), 0.0);
-		double sxy = std::inner_product(x_cent.begin(), x_cent.end(), y_cent.begin(), 0.0);
-
-		double denom = std::sqrt(sxx) * std::sqrt(syy);
-		if (denom <= 0)
+		if (sxx <= 0 || syy <= 0)
 			return std::numeric_limits<double>::quiet_NaN();
 
-		double r = sxy / denom;
+		double sxy = std::inner_product(x_cent.begin(), x_cent.end(), y_cent.begin(), 0.0);
+		double r = sxy / (std::sqrt(sxx) * std::sqrt(syy));
 		r = max(min(r, 1.0), -1.0);
 		return r;
 	}