Added more test, formatted with clang-format

Author: HarshilShah1804

.clang-tidy

@@ -2,5 +2,5 @@
 Checks:          '-*,google-*,clang-analyzer-*,-clang-analyzer-security.insecureAPI.*,cppcoreguidelines-*,-cppcoreguidelines-avoid-magic-numbers,-cppcoreguidelines-pro-bounds-*,openmp-*,performance-*,portability-*,modernize-*,-modernize-use-trailing-*'
 WarningsAsErrors: '*,-google-readability-*,-google-explicit-constructor,-modernize-*,modernize-avoid-c-arrays,-performance-move-const-arg,-performance-noexcept-move-constructor,-performance-unnecessary-value-param,-cppcoreguidelines-init-variables,-cppcoreguidelines-pro-*,-cppcoreguidelines-owning-memory,-clang-analyzer-cplusplus.Move'
 HeaderFilterRegex: ''
-AnalyzeTemporaryDtors: false
+# AnalyzeTemporaryDtors: false
 FormatStyle:     '{ BasedOnStyle: Google, UseTab: Never, IndentWidth: 4, TabWidth: 4, AllowShortIfStatementsOnASingleLine: false, IndentCaseLabels: true, ColumnLimit: 80, AccessModifierOffset: -3, AlignConsecutiveMacros: true }'

probability/exponential_dist.cpp

@@ -1,100 +1,103 @@
 /**
  * @file
- * @brief [Exponential Distribution](https://en.wikipedia.org/wiki/Exponential_distribution)
- * 
+ * @brief [Exponential
+ * Distribution](https://en.wikipedia.org/wiki/Exponential_distribution)
+ *
  * The exponential distribution is used to model
  * events occuring between a Poisson process like radioactive decay.
- * 
+ *
  * \f[P(x, \lambda) = \lambda e^{-\lambda x}\f]
- * 
+ *
  * Summary of variables used:
  * \f$\lambda\f$ : rate parameter
  */
 
-#include<cmath> // For std::pow
-#include<cassert> // For assert
-#include<iostream> // For I/O operation
+#include <cassert>   // For asserting the test cases
+#include <cmath>     // For power function
+#include <iostream>  // For I/O operation
 
-/** 
+/**
  * @brief the expected value of the exponential distribution
  * @returns \f[\mu = \frac{1}{\lambda}\f]
  */
-double exponential_expected(double lambda){
-    if (lambda<=0){
-        std::cout << "Error: Lambda must be greater than 0." << std::endl;
-        assert(lambda>0);
+double exponential_expected(double lambda) {
+    if (lambda <= 0) {
+        std::cout << "Error: Lambda must be greater than 0." << '\n';
+        assert(lambda > 0);
     }
-    return 1/lambda;
+    return 1 / lambda;
 }
 
-/** 
+/**
  * @brief the variance of the exponential distribution
  * @returns \f[\sigma^2 = \frac{1}{\lambda^2}\f]
  */
-double exponential_var(double lambda){
-    if (lambda<=0){
-        std::cout << "Error: Lambda must be greater than 0." << std::endl;
-        assert(lambda>0);
+double exponential_var(double lambda) {
+    if (lambda <= 0) {
+        std::cout << "Error: Lambda must be greater than 0." << '\n';
+        assert(lambda > 0);
     }
-    return 1/pow(lambda,2);
+    return 1 / pow(lambda, 2);
 }
 
-/** 
+/**
  * @brief the standard deviation of the exponential distribution
  * @returns \f[\sigma = \frac{1}{\lambda}\f]
  */
-double exponential_std(double lambda){
-    if (lambda<=0){
-        std::cout << "Error: Lambda must be greater than 0." << std::endl;
-        assert(lambda>0);
+double exponential_std(double lambda) {
+    if (lambda <= 0) {
+        std::cout << "Error: Lambda must be greater than 0." << '\n';
+        assert(lambda > 0);
     }
-    return 1/lambda;
+    return 1 / lambda;
 }
 
 /**
- * @brief Self-test implementation
+ * @brief Self-test implementations
  * @returns void
  */
-static void test(){
-    double lambda = 2;
-    double expected = 0.5;
-    double var = 0.25;
-    double std = 0.5;
+static void test() {
+    double lambda_1 = 1;
+    double expected_1 = 1;
+    double var_1 = 1;
+    double std_1 = 1;
+
+    double lambda_2 = 2;
+    double expected_2 = 0.5;
+    double var_2 = 0.25;
+    double std_2 = 0.5;
 
-    //Test 1
-    std::cout << "Expected Value" << std::endl;
-    std::cout << "Lambda : " << lambda << std::endl;
-    std::cout << "Expected Output : " << expected <<std::endl;
-    std::cout << "Output : " << exponential_expected(lambda) << std::endl;
-    assert(exponential_expected(lambda)==expected);
-    std::cout << "TEST PASSED" << std::endl;
-    std::cout<<std::endl;
+    double lambda_3 = 3;
+    double expected_3 = 0.333333;
+    double var_3 = 0.111111;
+    double std_3 = 0.333333;
 
-    //Test 2
-    std::cout << "Variance" << std::endl;
-    std::cout << "Lambda : " << lambda << std::endl;
-    std::cout << "Expected Output : " << var <<std::endl;
-    std::cout << "Output : " << exponential_var(lambda) << std::endl;
-    assert(exponential_var(lambda)==var);
-    std::cout << "TEST PASSED" << std::endl;
-    std::cout<<std::endl;
+    const float threshold = 1e-3f;
 
-    //Test 3
-    std::cout << "Standard Deviation" << std::endl;
-    std::cout << "Lambda : " << lambda << std::endl;
-    std::cout << "Expected Output : " << std <<std::endl;
-    std::cout << "Output : " << exponential_std(lambda) << std::endl;
-    assert(exponential_std(lambda)==std);
-    std::cout << "TEST PASSED" << std::endl;
-    std::cout<<std::endl;
+    std::cout << "Test for lambda = 1 \n";
+    assert(std::abs(expected_1 - exponential_expected(lambda_1)) < threshold);
+    assert(std::abs(var_1 - exponential_var(lambda_1)) < threshold);
+    assert(std::abs(std_1 - exponential_std(lambda_1)) < threshold);
+    std::cout << "ALL TEST PASSED\n\n";
+
+    std::cout << "Test for lambda = 2 \n";
+    assert(std::abs(expected_2 - exponential_expected(lambda_2)) < threshold);
+    assert(std::abs(var_2 - exponential_var(lambda_2)) < threshold);
+    assert(std::abs(std_2 - exponential_std(lambda_2)) < threshold);
+    std::cout << "ALL TEST PASSED\n\n";
+
+    std::cout << "Test for lambda = 3 \n";
+    assert(std::abs(expected_3 - exponential_expected(lambda_3)) < threshold);
+    assert(std::abs(var_3 - exponential_var(lambda_3)) < threshold);
+    assert(std::abs(std_3 - exponential_std(lambda_3)) < threshold);
+    std::cout << "ALL TEST PASSED\n";
 }
 
 /**
  * @brief Main function
  * @return 0 on exit
  */
-int main(){
-    test(); // Self test implementation
+int main() {
+    test();  // Self test implementation
     return 0;
 }
-