first commit - migrated from codeberg

native/statistics/basic_stats.cpp

@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: © 2025 Nøkken.io <nokken.io@proton.me>
+// SPDX-License-Identifier: AGPL-3.0
+//
+// basic_stats.cpp
+// Implementation of basic statistical analysis functions
+//
+#include "health_analytics_engine.h"
+#include "utils.h"
+/**
+ * @brief Calculate basic statistical properties of a data series
+ * 
+ * @param values Pointer to array of values
+ * @param length Number of elements in the array
+ * @return BasicStats Structure containing calculated statistics
+ */
+BasicStats calculate_basic_stats(const double* values, int length) {
+    BasicStats stats;
+    
+    if (length == 0) {
+        memset(&stats, 0, sizeof(BasicStats));
+        return stats;
+    }
+    
+    // Create a copy for calculations that require sorting
+    std::vector<double> sorted(values, values + length);
+    std::sort(sorted.begin(), sorted.end());
+    
+    // Calculate basic statistics
+    stats.mean = calculateMean(values, length);
+    stats.variance = calculateVariance(values, length, stats.mean);
+    stats.stdDev = std::sqrt(stats.variance);
+    stats.min = sorted.front();
+    stats.max = sorted.back();
+    stats.median = (length % 2 == 0) ? 
+        (sorted[length/2 - 1] + sorted[length/2]) / 2.0 : sorted[length/2];
+    
+    // Calculate quartiles and IQR
+    stats.q1 = calculateQuantile(sorted.data(), length, 0.25);
+    stats.q3 = calculateQuantile(sorted.data(), length, 0.75);
+    stats.iqr = stats.q3 - stats.q1;
+    
+    // Calculate higher-order statistics
+    stats.skewness = calculateSkewness(values, length, stats.mean, stats.stdDev);
+    stats.kurtosis = calculateKurtosis(values, length, stats.mean, stats.stdDev);
+    
+    return stats;
+}