update

2020.08.29_several_python_functions/get_eigenvalues_plot_and_write/get_eigenvalues_and_plot_1D_bands.py

@@ -0,0 +1,35 @@
+import numpy as np
+from math import *
+# import os
+# os.chdir('D:/data')  # 设置路径
+
+
+def hamiltonian(k):
+    pass
+
+
+def main():
+    k = np.arange(-pi, pi, 0.05)
+    plot_bands_one_dimension(k, hamiltonian)
+
+
+def plot_bands_one_dimension(k, hamiltonian):
+    import matplotlib.pyplot as plt
+    dim = hamiltonian(0).shape[0]
+    dim_k = k.shape[0]
+    eigenvalue_k = np.zeros((dim_k, dim))
+    i0 = 0
+    for k0 in k:
+        matrix0 = hamiltonian(k0)
+        eigenvalue, eigenvector = np.linalg.eig(matrix0)
+        eigenvalue_k[i0, :] = np.sort(np.real(eigenvalue[:]))
+        i0 += 1
+    for dim0 in range(dim):
+        plt.plot(k, eigenvalue_k[:, dim0], '-k')
+    plt.xlabel('k')
+    plt.ylabel('E') 
+    plt.show()
+
+
+if __name__ == '__main__':
+    main()

2020.08.29_several_python_functions/get_eigenvalues_plot_and_write/get_eigenvalues_and_plot_2D_bands.py

@@ -0,0 +1,47 @@
+import numpy as np
+from math import *
+# import os
+# os.chdir('D:/data')  # 设置路径
+
+
+def hamiltonian(k1, k2):
+    pass
+
+
+def main():
+    k1 = np.arange(-pi, pi, 0.05)
+    k2 = np.arange(-pi, pi, 0.05)
+    plot_bands_two_dimension(k1, k2, hamiltonian)
+
+
+def plot_bands_two_dimension(k1, k2, hamiltonian):
+    import matplotlib.pyplot as plt
+    from mpl_toolkits.mplot3d import Axes3D
+    from matplotlib import cm
+    from matplotlib.ticker import LinearLocator, FormatStrFormatter
+    dim = hamiltonian(0, 0).shape[0]
+    dim1 = k1.shape[0]
+    dim2 = k2.shape[0]
+    eigenvalue_k = np.zeros((dim2, dim1, dim))
+    i0 = 0
+    for k20 in k2:
+        j0 = 0
+        for k10 in k1:
+            matrix0 = hamiltonian(k10, k20)
+            eigenvalue, eigenvector = np.linalg.eig(matrix0)
+            eigenvalue_k[i0, j0, :] = np.sort(np.real(eigenvalue[:]))
+            j0 += 1
+        i0 += 1
+    fig = plt.figure()
+    ax = fig.gca(projection='3d')
+    k1, k2 = np.meshgrid(k1, k2)
+    for dim0 in range(dim):
+        ax.plot_surface(k1, k2, eigenvalue_k[:, :, dim0], cmap=cm.coolwarm, linewidth=0, antialiased=False) 
+    plt.xlabel('k1')
+    plt.ylabel('k2') 
+    ax.set_zlabel('E')  
+    plt.show()
+
+
+if __name__ == '__main__':
+    main()

2020.08.29_several_python_functions/get_eigenvalues_plot_and_write/get_eigenvalues_and_write_1D_data_into_txt_file.py

@@ -0,0 +1,31 @@
+import numpy as np
+from math import *
+# import os
+# os.chdir('D:/data')  # 设置路径
+
+
+def hamiltonian(k):
+    pass
+
+
+def main():
+    k = np.arange(-pi, pi, 0.05)
+    write_bands_one_dimension(k, hamiltonian)
+
+
+def write_bands_one_dimension(k, hamiltonian):
+    dim = hamiltonian(0).shape[0]
+    f = open('a.txt','w')
+    for k0 in k:
+        f.write(str(k0)+'   ')
+        matrix0 = hamiltonian(k0)
+        eigenvalue, eigenvector = np.linalg.eig(matrix0)
+        eigenvalue = np.sort(np.real(eigenvalue))
+        for dim0 in range(dim):
+            f.write(str(eigenvalue[dim0])+'   ')
+        f.write('\n')
+    f.close()
+
+
+if __name__ == '__main__':
+    main()

2020.08.29_several_python_functions/get_eigenvalues_plot_and_write/get_eigenvalues_and_write_2D_data_into_txt_file.py

@@ -0,0 +1,42 @@
+import numpy as np
+from math import *
+# import os
+# os.chdir('D:/data')  # 设置路径
+
+
+def hamiltonian(k1, k2):
+    pass
+
+
+def main():
+    k1 = np.arange(-pi, pi, 0.05)
+    k2 = np.arange(-pi, pi, 0.05)
+    write_bands_two_dimension(k1, k2, hamiltonian)
+
+
+def write_bands_two_dimension(k1, k2, hamiltonian):
+    f1 = open('a1.txt', 'w')
+    f2 = open('a2.txt', 'w')
+    f1.write('0     ')
+    f2.write('0     ')
+    for k10 in k1:
+        f1.write(str(k10)+'   ')
+        f2.write(str(k10)+'   ')
+    f1.write('\n')
+    f2.write('\n')
+    for k20 in k2:
+        f1.write(str(k20)+'   ')
+        f2.write(str(k20)+'   ')
+        for k10 in k1:
+            matrix0 = hamiltonian(k10, k20)
+            eigenvalue, eigenvector = np.linalg.eig(matrix0)
+            eigenvalue = np.sort(np.real(eigenvalue))
+            f1.write(str(eigenvalue[0])+'   ')
+            f2.write(str(eigenvalue[1])+'   ')
+        f1.write('\n')
+        f2.write('\n')
+    f1.close()
+    f2.close()
+
+if __name__ == '__main__':
+    main()