Merge pull request #22 from Anonymous5164/master

Added stats.cpp

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; 
+        }
+    }
+}

test/stats.cpp

@@ -0,0 +1,42 @@
+#include <iostream>
+#include "../stats.cpp" 
+using namespace std;
+
+
+int main() {
+
+    float arr[] = {1.2, 2.5, 3.1, 4.8, 5.3};
+    int len = sizeof(arr) / sizeof(arr[0]);
+
+    // Test arrayMean
+    float mean = mlb::arrayMean(arr, len);
+    cout << "Mean: " << mean << endl;
+
+    // Test arrayMedian
+    float median = mlb::arrayMedian(arr, len);
+    cout << "Median: " << median << endl;
+
+    // Test arrayMode
+    float mode = mlb::arrayMode(arr, len);
+    cout << "Mode: " << mode << endl;
+
+    // Test normalPDF
+    float x = 2.0;
+    float pdf = mlb::normalPDF(x, 0.0, 1.0);
+    cout << "Normal PDF at x=" << x << ": " << pdf << endl;
+
+    // Test exponentialPDF
+    float lambda = 0.5;
+    x = 1.0;
+    float exp_pdf = mlb::exponentialPDF(x, lambda);
+    cout << "Exponential PDF at x=" << x << ": " << exp_pdf << endl;
+
+    // Test binomialPMF
+    int k = 2;
+    int n = 5;
+    float p = 0.3;
+    float binomial_pmf = mlb::binomialPMF(k, n, p);
+    cout << "Binomial PMF at k=" << k << ", n=" << n << ", p=" << p << ": " << binomial_pmf << endl;
+
+    return 0;
+}