bug: fixed argument order in nanoribbon

It was not consistent across the different ribbon
creation routines. Now they are.

CHANGELOG.md

@@ -53,6 +53,7 @@ we hit release version 1.0.0.
 - fixed hpc parameters #403
 
 ### Changed
+- order of arguments for `nanoribbon` it was not consistent with the others
 - removed cell argument in `Geometry.sub`
 - removed `Sile.exist`, refer to `Sile.file` which always will be a `pathlib.Path` instance
 - `berry_phase` now uses the gauge=R convention, the code became much simpler

sisl/geom/nanoribbon.py

@@ -11,19 +11,19 @@
 
 
 @set_module("sisl.geom")
-def nanoribbon(bond, atoms, width, kind='armchair'):
+def nanoribbon(width, bond, atoms, kind='armchair'):
     r""" Construction of a nanoribbon unit cell of type armchair or zigzag.
 
     The geometry is oriented along the :math:`x` axis.
 
     Parameters
     ----------
+    width : int
+       number of atoms in the transverse direction
     bond : float
        bond length between atoms in the honeycomb lattice
     atoms : Atom
        atom (or atoms) in the honeycomb lattice
-    width : int
-       number of atoms in the transverse direction
     kind : {'armchair', 'zigzag'}
        type of ribbon
 
@@ -105,7 +105,7 @@ def graphene_nanoribbon(width, bond=1.42, atoms=None, kind='armchair'):
     """
     if atoms is None:
         atoms = Atom(Z=6, R=bond * 1.01)
-    return nanoribbon(bond, atoms, width, kind=kind)
+    return nanoribbon(width, bond, atoms, kind=kind)
 
 
 @set_module("sisl.geom")

sisl/geom/tests/test_geom.py

@@ -64,16 +64,16 @@ def test_bilayer():
 
 def test_nanoribbon():
     for w in range(0, 5):
-        a = nanoribbon(1.42, Atom(6), w, kind='armchair')
-        a = nanoribbon(1.42, Atom(6), w, kind='zigzag')
-        a = nanoribbon(1.42, (Atom(5), Atom(7)), w, kind='armchair')
-        a = nanoribbon(1.42, (Atom(5), Atom(7)), w, kind='zigzag')
+        a = nanoribbon(w, 1.42, Atom(6), kind='armchair')
+        a = nanoribbon(w, 1.42, Atom(6), kind='zigzag')
+        a = nanoribbon(w, 1.42, (Atom(5), Atom(7)), kind='armchair')
+        a = nanoribbon(w, 1.42, (Atom(5), Atom(7)), kind='zigzag')
 
     with pytest.raises(ValueError):
-        nanoribbon(1.42, (Atom(5), Atom(7)), 6, kind='undefined')
+        nanoribbon(6, 1.42, (Atom(5), Atom(7)), kind='undefined')
 
     with pytest.raises(ValueError):
-        nanoribbon(1.42, (Atom(5), Atom(7)), 'str', kind='undefined')
+        nanoribbon('str', 1.42, (Atom(5), Atom(7)), kind='undefined')
 
 
 def test_graphene_nanoribbon():