Updates

include/IsingModel.hpp

@@ -27,10 +27,11 @@
 #define DOWN 1
 #define RIGHT 1
 
+
 /** @brief The Ising model in 2 dimensions.
  *
- *  @details Here we set \f$ J = 1 \f$, and the Boltzmann constant
- *  \f$ k_B = 1 \f$.
+ *  @details None of the methods are parallelized, as there is very little
+ *  benefit in doing so.
  * */
 class IsingModel {
 private:
@@ -39,16 +40,26 @@ private:
      * */
     arma::Mat<int> lattice;
 
+    /** @brief \f$ L \cross 2 \f$ matrix with the neighbors of each element 
+     *  \f$ x_i \f$.
+     *
+     *  @details The reason why it's \f$ L \cross 2 \f$ instead of 
+     *  \f$ L \cross 2 \f$, is that we can see that we can use the same column
+     *  for the left and upper neighbor, and we can use the same column for the
+     *  right and lower neighbor.
+     * */
     arma::Mat<uint> neighbors;
 
     /** @brief A hash map containing all possible energy changes.
      * */
     std::unordered_map<int, double> energy_diff;
 
-    /** @brief Temperature
+    /** @brief The temperature of the model.
      * */
     double T;
 
+    /** @brief Size of the lattice.
+     * */
     uint L;
 
     /** @brief The current energy state. unit: \f$ J \f$.
@@ -72,32 +83,57 @@ private:
      * */
     void initialize_lattice();
 
+    /** @brief initialize the neighbors matrix.
+     * */
     void initialize_neighbors();
 
     /** @brief Initialize the hashmap with the correct values.
      * */
     void initialize_energy_diff();
 
-    /** @brief Initialize the model.
+    /** @brief Initialize the magnetization.
      * */
     void initialize_magnetization();
 
+    /** @brief Initialize the energy.
+     * */
     void initialize_energy();
 
+    /** @brief Constructor used for testing.
+     * */
+    IsingModel();
+
 public:
     /** @brief Constructor for the Ising model.
      *
      *  @param L The size of the lattice.
+     *  @param T The temperature for the system.
      * */
     IsingModel(uint L, double T);
 
     /** @brief Constructor for the Ising model.
      *
      *  @param L The size of the lattice.
+     *  @param T The temperature for the system.
+     *  @param val The value to set for all spins.
      * */
     IsingModel(uint L, double T, int val);
 
+    /** @brief The Metropolis algorithm.
+     * */
     void Metropolis(std::mt19937 engine);
+
+    /** @brief Get the current energy.
+     *
+     *  @return int
+     * */
+    int get_E();
+
+    /** @brief Get the current magnetization.
+     *
+     *  @return int
+     * */
+    int get_M();
 };
 
 #endif

src/IsingModel.cpp

@@ -14,8 +14,13 @@
 
 #include "constants.hpp"
 
+#include <cmath>
 #include <random>
 
+IsingModel::IsingModel()
+{
+}
+
 IsingModel::IsingModel(uint L, double T)
 {
     this->L = L;
@@ -55,11 +60,11 @@ void IsingModel::initialize_neighbors()
 {
     this->neighbors.set_size(this->L, 2);
 
-    for (int i = 0; i < this->L; i++) {
+    // Having i as a signed integer is necessary in this case.
+    for (int i = 0; i < (int)this->L; i++) {
         this->neighbors(i, UP) = INDEX(i - 1, this->L);
         this->neighbors(i, DOWN) = INDEX(i + 1, this->L);
     }
-    this->neighbors.print();
 }
 
 void IsingModel::initialize_energy_diff()
@@ -98,7 +103,7 @@ void IsingModel::Metropolis(std::mt19937 engine)
     std::uniform_real_distribution<> random_number(0., 1.);
 
     // Loop over the number of spins
-    for (int i = 0; i < this->lattice.n_elem; i++) {
+    for (size_t i = 0; i < this->lattice.n_elem; i++) {
         // Get random indeces
         ri = random_index(engine);
         rj = random_index(engine);
@@ -119,3 +124,13 @@ void IsingModel::Metropolis(std::mt19937 engine)
         }
     }
 }
+
+int IsingModel::get_E()
+{
+    return this->E;
+}
+
+int IsingModel::get_M()
+{
+    return this->M;
+}