style: remove interaction with the user

math/vector_cross_product.cpp

@@ -1,19 +1,22 @@
 /**
  * @file
  *
- * @brief Calculates the [Cross Product](https://en.wikipedia.org/wiki/Cross_product) and the magnitude of two mathematical 3D vectors.
+ * @brief Calculates the [Cross
+ *Product](https://en.wikipedia.org/wiki/Cross_product) and the magnitude of two
+ *mathematical 3D vectors.
  *
  *
  * @details Cross Product of two vectors gives a vector.
- * Direction Ratios of a vector are the numeric parts of the given vector. They are the tree parts of the
- * vector which determine the magnitude (value) of the vector.
- * The method of finding a cross product is the same as finding the determinant of an order 3 matrix consisting
- * of the first row with unit vectors of magnitude 1, the second row with the direction ratios of the
- * first vector and the third row with the direction ratios of the second vector.
- * The magnitude of a vector is it's value expressed as a number.
- * Let the direction ratios of the first vector, P be: a, b, c
- * Let the direction ratios of the second vector, Q be: x, y, z
- * Therefore the calculation for the cross product can be arranged as:
+ * Direction Ratios of a vector are the numeric parts of the given vector. They
+ *are the tree parts of the vector which determine the magnitude (value) of the
+ *vector. The method of finding a cross product is the same as finding the
+ *determinant of an order 3 matrix consisting of the first row with unit vectors
+ *of magnitude 1, the second row with the direction ratios of the first vector
+ *and the third row with the direction ratios of the second vector. The
+ *magnitude of a vector is it's value expressed as a number. Let the direction
+ *ratios of the first vector, P be: a, b, c Let the direction ratios of the
+ *second vector, Q be: x, y, z Therefore the calculation for the cross product
+ *can be arranged as:
  *
  * ```
  * P x Q:
@@ -28,11 +31,13 @@
  *  	3rd DR, N:  (a * y) - (b * x)
  *
  * Therefore, the direction ratios of the cross product are: J, A, N
- * The following C++ Program calculates the direction ratios of the cross products of two vector.
- * The program uses a function, cross() for doing so.
- * The direction ratios for the first and the second vector has to be passed one by one seperated by a space character.
+ * The following C++ Program calculates the direction ratios of the cross
+ *products of two vector. The program uses a function, cross() for doing so. The
+ *direction ratios for the first and the second vector has to be passed one by
+ *one seperated by a space character.
  *
- * Magnitude of a vector is the square root of the sum of the squares of the direction ratios.
+ * Magnitude of a vector is the square root of the sum of the squares of the
+ *direction ratios.
  *
  * ### Example:
  * An example of a running instance of the executable program:
@@ -45,89 +50,83 @@
  * @author [Shreyas Sable](https://github.com/Shreyas-OwO)
  */
 
-#include <iostream>
 #include <array>
-#include <cmath>
 #include <cassert>
+#include <cmath>
 
 /**
  * @namespace math
  * @brief Math algorithms
  */
 namespace math {
-	/**
-	 * @namespace vector_cross
-	 * @brief Functions for Vector Cross Product algorithms
-	 */
-	namespace vector_cross {
-		/**
-		 * @brief Function to calculate the cross product of the passed arrays containing the direction ratios of the two mathematical vectors.
-		 * @param A contains the direction ratios of the first mathematical vector.
-		 * @param B contains the direction ration of the second mathematical vector.
-		 * @returns the direction ratios of the cross product.
-		 */
-		std::array<double, 3> cross(const std::array<double, 3> &A, const std::array<double, 3> &B) {
-			std::array<double, 3> product;
-			/// Performs the cross product as shown in @algorithm.
-			product[0] = (A[1] * B[2]) - (A[2] * B[1]);
-			product[1] = -((A[0] * B[2]) - (A[2] * B[0]));
-			product[2] = (A[0] * B[1]) - (A[1] * B[0]);
-			return product;
-		}
+/**
+ * @namespace vector_cross
+ * @brief Functions for Vector Cross Product algorithms
+ */
+namespace vector_cross {
+/**
+ * @brief Function to calculate the cross product of the passed arrays
+ * containing the direction ratios of the two mathematical vectors.
+ * @param A contains the direction ratios of the first mathematical vector.
+ * @param B contains the direction ration of the second mathematical vector.
+ * @returns the direction ratios of the cross product.
+ */
+std::array<double, 3> cross(const std::array<double, 3> &A,
+                            const std::array<double, 3> &B) {
+    std::array<double, 3> product;
+    /// Performs the cross product as shown in @algorithm.
+    product[0] = (A[1] * B[2]) - (A[2] * B[1]);
+    product[1] = -((A[0] * B[2]) - (A[2] * B[0]));
+    product[2] = (A[0] * B[1]) - (A[1] * B[0]);
+    return product;
+}
 
-		/**
-		 * @brief Calculates the magnitude of the mathematical vector from it's direction ratios.
-		 * @param vec an array containing the direction ratios of a mathematical vector.
-		 * @returns type: double description: the magnitude of the mathematical vector from the given direction ratios.
-		 */
-		double mag(const std::array<double, 3> &vec) {
-			double magnitude = sqrt((vec[0] * vec[0]) + (vec[1] * vec[1]) + (vec[2] * vec[2]));
-			return magnitude;
-		}
-	} /// namespace vector_cross
-} /// namespace math
+/**
+ * @brief Calculates the magnitude of the mathematical vector from it's
+ * direction ratios.
+ * @param vec an array containing the direction ratios of a mathematical vector.
+ * @returns type: double description: the magnitude of the mathematical vector
+ * from the given direction ratios.
+ */
+double mag(const std::array<double, 3> &vec) {
+    double magnitude =
+        sqrt((vec[0] * vec[0]) + (vec[1] * vec[1]) + (vec[2] * vec[2]));
+    return magnitude;
+}
+}  // namespace vector_cross
+}  // namespace math
 
 /**
  * @brief test function.
  * @details test the cross() and the mag() functions.
  */
 static void test() {
-	/// Tests the cross() function.
-	std::array<double, 3> t_vec = math::vector_cross::cross({1, 2, 3}, {4, 5, 6});
-	assert(t_vec[0] == -3 && t_vec[1] == 6 && t_vec[2] == -3);
+    /// Tests the cross() function.
+    std::array<double, 3> t_vec =
+        math::vector_cross::cross({1, 2, 3}, {4, 5, 6});
+    assert(t_vec[0] == -3 && t_vec[1] == 6 && t_vec[2] == -3);
+
+    /// Tests the mag() function.
+    double t_mag = math::vector_cross::mag({6, 8, 0});
+    assert(t_mag == 10);
 
-	/// Tests the mag() function.
-	double t_mag = math::vector_cross::mag({6, 8, 0});
-	assert(t_mag == 10);
+    /// Tests A ⨯ A = 0
+    std::array<double, 3> t_vec2 =
+        math::vector_cross::cross({1, 2, 3}, {1, 2, 3});
+    assert(t_vec2[0] == 0 && t_vec2[1] == 0 &&
+           t_vec2[2] == 0);  // checking each element
+    assert(math::vector_cross::mag(t_vec2) ==
+           0);  // checking the magnitude is also zero
 }
 
 /**
  * @brief Main Function
- * @details Asks the user to enter the direction ratios for each of the two mathematical vectors using std::cin
+ * @details Asks the user to enter the direction ratios for each of the two
+ * mathematical vectors using std::cin
  * @returns 0 on exit
  */
 int main() {
-
-	/// Tests the functions with sample input before asking for user input.
-	test();
-
-	std::array<double, 3> vec1;
-	std::array<double, 3> vec2;
-
-	/// Gets the values for the first vector.
-	std::cout << "\nPass the first Vector: ";
-	std::cin >> vec1[0] >> vec1[1] >> vec1[2];
-
-	/// Gets the values for the second vector.
-	std::cout << "\nPass the second Vector: ";
-	std::cin >> vec2[0] >> vec2[1] >> vec2[2];
-
-	/// Displays the output out.
-	std::array<double, 3> product = math::vector_cross::cross(vec1, vec2);
-	std::cout << "\nThe cross product is: " << product[0] << " " << product[1] << " " << product[2] << std::endl;
-
-	/// Displays the magnitude of the cross product.
-	std::cout << "Magnitude: " << math::vector_cross::mag(product) << "\n" << std::endl;
-
-	return 0;
+    /// Tests the functions with sample input before asking for user input.
+    test();
+    return 0;
 }