Fix 'sym', 0 behaviour and tutorial 4 #205

Author: mducle

swfiles/@spinw/genlattice.m

@@ -129,11 +129,14 @@
             ' instead']);
     if ~isempty(param.sym)
         error('spinw:genlattice:WrongInput', ...
-            'Both sym and spgr provided - note sym will be used.');
+            'Both sym and spgr provided - please only use sym.');
     else
         param.sym = param.spgr;
     end
 end
+if isnumeric(param.sym) && param.sym == 0
+    param.sym = [];
+end
 if any(strcmp('angled', varargin(1:2:end))) && ...
         any(strcmp('angle', varargin(1:2:end)))
 	warning('spinw:genlattice:WrongInput', ...
@@ -293,4 +296,4 @@
 
 obj.unit.nformula = int32(param.nformula);
 
-end
+end

tutorials/publish/tutorial4.m

@@ -2,7 +2,7 @@
 % We define a square lattice in the ab plane, with Cu+ ions with S=1 spin.
 
 AFsq = spinw;
-AFsq.genlattice('lat_const',[3 3 6],'angled',[90 90 90],'sym',0)
+AFsq.genlattice('lat_const',[3 3 6],'angled',[90 90 90])
 AFsq.addatom('r',[0 0 0],'S', 1,'label','Cu1','color','b')
 AFsq.table('atom')
 plot(AFsq)