Added stats.cpp

Author: Anonymous5164

stats.cpp

@@ -0,0 +1,70 @@
+#include <cmath>
+#include <vector>
+#include <algorithm>
+#include <unordered_map>
+using namespace std;
+
+namespace mlb {
+    
+    float arrayMean(float arr[], int len) {
+        float sum = 0.0;
+        for (int i = 0; i < len; i++) {
+            sum += arr[i];
+        }
+        return sum / len;
+    }
+
+    float arrayMedian(float arr[], int len) {
+        vector<float> sortedArr(arr, arr + len);
+        sort(sortedArr.begin(), sortedArr.end());
+        
+        if (len % 2 == 0) {
+            float middle1 = sortedArr[len / 2 - 1];
+            float middle2 = sortedArr[len / 2];
+            return (middle1 + middle2) / 2.0;
+        } 
+        else {
+            return sortedArr[len / 2];
+        }
+    }
+
+    float arrayMode(float arr[], int len) {
+        unordered_map<float, int> countMap;
+        int maxCount = 0;
+        float mode = 0.0;
+
+        for (int i = 0; i < len; i++) {
+            countMap[arr[i]]++;
+            if (countMap[arr[i]] > maxCount) {
+                maxCount = countMap[arr[i]];
+                mode = arr[i];
+            }
+        }
+
+        return mode;
+    }
+
+    float normalPDF(float x, float mean, float stddev) {
+        float exponent = -(pow(x - mean, 2) / (2 * pow(stddev, 2)));
+        return (1 / (stddev * sqrt(2 * M_PI))) * exp(exponent);
+    }
+
+    float exponentialPDF(float x, float lambda) {
+        if (x >= 0) {
+            return lambda * exp(-lambda * x);
+        } 
+        else {
+            return 0.0; 
+        }
+    }
+
+    float binomialPMF(int k, int n, float p) {
+        if (k >= 0 && k <= n) {
+            float binomialCoefficient = tgamma(n + 1) / (tgamma(k + 1) * tgamma(n - k + 1));
+            return binomialCoefficient * pow(p, k) * pow(1 - p, n - k);
+        } 
+        else {
+            return 0.0; 
+        }
+    }
+}