initial commit

Author: jjdredd

IsingMC/IsingMC.cpp

@@ -0,0 +1,86 @@
+#include "IsingMC.hpp"
+
+#include <iostream>
+
+#include <cmath>
+#include <cstdlib>
+
+IsingMC::IsingMC(unsigned M, unsigned N, double J, double beta)
+	: M(M), N(N), J(J), beta(beta) {
+
+	Lattice = new int[M];
+	for (unsigned i = 0; i < M; i++) {
+		Lattice[i] = new int[N];
+	}
+
+	for (unsigned i = 0; i < M; i++) {
+		for (unsigned j = 0; j < N; j++) {
+			if (random() % 2 == 0) Lattice[i][j] = 1;
+			else Lattice[i][j] = -1;
+		}
+	}
+}
+
+IsingMC::~IsingMC() {
+
+	for (unsigned i = 0; i < M; i++) {
+		delete[] Lattice[i];
+	}
+	delete[] Lattice;
+	Lattice = NULL;
+}
+
+void IsingMC::RandomPoint(unsigned& m, unsigned& n) {
+
+	unsigned pos = static_cast<unsigned>
+		(floor (static_cast<double> (random()) / RAND_MAX * M * N));
+
+	m = static_cast<unsigned> (floor (pos / N));
+	n = pos - m * N;
+}
+
+double IsingMC::SpinEnergy(unsigned m, unsigned n) {
+
+	double E = 0;
+	for (unsigned i = m - 1 ; i < m + 1; i += 2) {
+		for (unsigned j = n - 1; j < n + 1; j += 2) {
+
+			if (i < 0) ii = M - 1;
+			else if (i >= M - 1) ii = 0;
+			else ii = i;
+
+			if (j < 0) jj = N - 1;
+			else if (j >= N - 1) jj = 0;
+			else jj = j;
+
+			E -= Lattice[ii][jj] * Lattice[m][n] * J;
+		}
+	}
+	return E;
+}
+
+double IsingMC::Energy() {
+
+	double E = 0;
+	for (unsigned i = 0; i < M; i++) {
+		for (unsigned j = 0; j < N; j++) {
+			E += SpinEnergy(i, j);
+		}
+	}
+	return E;
+}
+
+void IsingMC::Step() {
+
+	unsigned i, j;
+	RandomPoint(i, j);
+
+	double E_1 = Energy();
+	Lattice[i][j] = -Lattice[i][j];
+
+	double E_2 = Energy();
+
+	if (E_2 < E_1) return;
+
+	if ()
+}

IsingMC/IsingMC.hpp

@@ -0,0 +1,23 @@
+#ifndef _ISINGMC_
+#define _ISINGMC_
+
+class IsingMC {
+
+public:
+	IsingMC(unsigned, unsigned, double, double);
+	~IsingMC();
+	double Energy();
+	void Step();
+
+private:
+	unsigned N, M;
+	int **Lattice;
+	double J, beta;
+
+
+	void RandomPoint(unsigned&, unsigned&);
+	double SpinEnergy(unsigned, unsigned);
+	
+}
+
+#endif _ISINGMC_ 		// #ifndef _ISINGMC_