Interface refactoring

Find a design which is more intuitive and minimal.

codes/tb/test_tb.py

 # %%
 import numpy as np
 from codes.tb.tb import compareDicts
+from codes.kwant_helper import utils
 import itertools as it
-from codes.tb.transforms import kfunc2tb, tb2kfunc
+from codes.tb.transforms import kfunc2tb, tb2kfunc, tb2kham, tb2khamvector
 import pytest
+
 repeatNumber = 10
 
 # %%
@@ -12,6 +14,7 @@ maxOrder = 5
 matrixSize = 5
 nK = 10
 
+
 @pytest.mark.repeat(repeatNumber)
 def test_fourier():
     keys = [np.arange(-maxOrder + 1, maxOrder) for i in range(ndim)]
@@ -19,4 +22,23 @@ def test_fourier():
     h_0 = {key: (np.random.rand(matrixSize, matrixSize) - 0.5) * 2 for key in keys}
     kfunc = tb2kfunc(h_0)
     tb_new = kfunc2tb(kfunc, nK, ndim=ndim)
-    compareDicts(h_0, tb_new)
\ No newline at end of file
+    compareDicts(h_0, tb_new)
+
+
+@pytest.mark.repeat(repeatNumber)
+def test_tbkham_transform():
+    vectors = (
+        (0, 0),
+        (1, 0),
+        (-1, 0),
+        (0, 1),
+        (0, -1),
+        (1, -1),
+        (-1, 1),
+        (1, 1),
+        (-1, -1),
+    )
+    ndof = 10
+    h_0 = utils.generate_guess(vectors, ndof)
+
+    assert np.allclose(tb2kham(h_0, nK=nK, ndim=2), tb2khamvector(h_0, nK=nK, ndim=2))