diff --git a/+vis/checker3.m b/+vis/checker3.m
index 259fdd5..687f977 100644
--- a/+vis/checker3.m
+++ b/+vis/checker3.m
@@ -4,7 +4,6 @@
 
 elem = t.Node.Net.subscriptableOrigin('checker');
 
-% defRectSize = [10 10];
 %% make initial layers to be used as templates
 maskTemplate = vis.emptyLayer();
 maskTemplate.isPeriodic = false;
diff --git a/+vis/grating.m b/+vis/grating.m
index 3af2df5..2785437 100644
--- a/+vis/grating.m
+++ b/+vis/grating.m
@@ -10,6 +10,8 @@
   grating = 'sinusoid';
 end
 elem = t.Node.Net.subscriptableOrigin('gabor');
+elem.grating = grating;
+elem.window = window;
 elem.azimuth = 0;
 elem.altitude = 0;
 elem.sigma = [10 10];
@@ -20,50 +22,48 @@
 elem.show = false;
 
 elem.layers = elem.map(@makeLayers).flattenStruct();
+end
+
+function layers = makeLayers(newelem)
+%% make a grating layer of the specified type
+switch lower(newelem.grating)
+  case {'sinusoid' 'sine' 'sin'}
+    [gratingLayer, gratingImg] = vis.sinusoidLayer(newelem.azimuth,...
+      newelem.spatialFreq, newelem.phase, newelem.orientation);
+    gratingLayer.textureId = 'sinusoidGrating';
+  case {'squarewave' 'square' 'sq'}
+    [gratingLayer, gratingImg] = vis.squareWaveLayer(newelem.azimuth,...
+      newelem.spatialFreq, newelem.phase, newelem.orientation);
+    gratingLayer.textureId = 'squareWaveGrating';
+  otherwise
+    error('Invalid grating type ''%s''', grating);
+end
+[gratingLayer.rgba, gratingLayer.rgbaSize] = vis.rgba(gratingImg, 1);
+gratingLayer.blending = 'destination';
+l = 0.5 - 0.5*newelem.contrast;
+h = 0.5 + 0.5*newelem.contrast;
+gratingLayer.minColour = l.*[1 1 1 0];
+gratingLayer.maxColour = [h.*ones(1, 3) 1];
+gratingLayer.show = newelem.show;
 
-  function layers = makeLayers(newelem)
-    clear elem t; % eliminate references to unsed outer variables
-    %% make a grating layer of the specified type
-    switch lower(grating)
-      case {'sinusoid' 'sine' 'sin'}
-        [gratingLayer, gratingImg] = vis.sinusoidLayer(newelem.azimuth,...
-          newelem.spatialFreq, newelem.phase, newelem.orientation);
-        gratingLayer.textureId = 'sinusoidGrating';
-      case {'squarewave' 'square' 'sq'}
-        [gratingLayer, gratingImg] = vis.squareWaveLayer(newelem.azimuth,...
-          newelem.spatialFreq, newelem.phase, newelem.orientation);
-        gratingLayer.textureId = 'squareWaveGrating';
-      otherwise
-        error('Invalid grating type ''%s''', grating);
-    end
-    [gratingLayer.rgba, gratingLayer.rgbaSize] = vis.rgba(gratingImg, 1);
-    gratingLayer.blending = 'destination';
-    l = 0.5 - 0.5*newelem.contrast;
-    h = 0.5 + 0.5*newelem.contrast;
-    gratingLayer.minColour = l.*[1 1 1 0];
-    gratingLayer.maxColour = [h.*ones(1, 3) 1];
-    gratingLayer.show = newelem.show;
-    
-    %% make a stencil layer using a window of the specified type
-    if ~strcmpi(window, 'none')
-      switch lower(window)
-        case {'gaussian' 'gauss'}
-          [winLayer, winImg] = vis.gaussianLayer(...
-            [newelem.azimuth; newelem.altitude], newelem.sigma);
-          winLayer.textureId = 'gaussianStencil';
-        otherwise
-          error('Invalid window type ''%s''', window);
-      end
-      [winLayer.rgba, winLayer.rgbaSize] = vis.rgba(0, winImg);
-      winLayer.blending = 'none';
-      winLayer.colourMask = [false false false true];
-      winLayer.show = newelem.show;
-    else % no window
-      winLayer = [];
-    end
-    
-    % window layer rendered first like a stencil
-    layers = [winLayer, gratingLayer];
+%% make a stencil layer using a window of the specified type
+if ~strcmpi(newelem.window, 'none')
+  switch lower(newelem.window)
+    case {'gaussian' 'gauss'}
+      [winLayer, winImg] = vis.gaussianLayer(...
+        [newelem.azimuth; newelem.altitude], newelem.sigma);
+      winLayer.textureId = 'gaussianStencil';
+    otherwise
+      error('Invalid window type ''%s''', window);
   end
+  [winLayer.rgba, winLayer.rgbaSize] = vis.rgba(0, winImg);
+  winLayer.blending = 'none';
+  winLayer.colourMask = [false false false true];
+  winLayer.show = newelem.show;
+else % no window
+  winLayer = [];
+end
 
+% window layer rendered first like a stencil
+layers = [winLayer, gratingLayer];
 end
\ No newline at end of file
diff --git a/+vis/rgba.m b/+vis/rgba.m
index f4feb2e..5de23b1 100644
--- a/+vis/rgba.m
+++ b/+vis/rgba.m
@@ -10,7 +10,7 @@
 alpha = uint8(round(255*alpha));
 
 if ~isscalar(colour) && size(colour, 3) == 1 % overall luminance specified
-  colour = repmat(colour, 1, 1, 3); % replicate to rgb
+  colour = repmat(colour, [1, 1, 3]); % replicate to rgb
 end
 
 img = zeros(h, w, 4, 'uint8');