image tests of contour labels

Author: alexcjohnson

test/image/baselines/contour_edge_cases.png

@@ -8,7 +8,13 @@
       "contours": {
         "start": 1.1,
         "end": 4.09,
-        "size": 1
+        "size": 1,
+        "showlabels": true,
+        "labelformat": ".3f",
+        "labelfont": {
+            "size": "8",
+            "color": "#0f0"
+        }
       },
       "colorbar": {"x": 0.4, "y": 0.9, "len": 0.2}
     },
@@ -35,7 +41,9 @@
       "contours": {
         "start": -0.000001,
         "end": 0.000001,
-        "size": 0.000001
+        "size": 0.000001,
+        "showlabels": true,
+        "labelformat": ".1e"
       },
       "colorbar": {"x": 0.4, "y": 0.65, "len": 0.2},
       "yaxis": "y2"
@@ -50,7 +58,11 @@
       "contours": {
         "start": -0.000001,
         "end": 0.000001,
-        "size": 0.000001
+        "size": 0.000001,
+        "showlabels": true
+      },
+      "line": {
+        "color": "#fff"
       },
       "colorbar": {"x": 1, "y": 0.65, "len": 0.2},
       "xaxis": "x2",
@@ -66,9 +78,10 @@
       "contours": {
         "start": -0.000001,
         "end": 0.000001,
-        "size": 0.000001
+        "size": 0.000001,
+        "showlabels": true
       },
-      "colorbar": {"x": 0.4, "y": 0.4, "len": 0.2},
+      "showscale": false,
       "yaxis": "y3"
     },
     {

test/image/baselines/contour_nolines.png

@@ -1,13 +1,19 @@
 {
   "data":[{
-    "contours":{"coloring":"fill","showlines":false},
-    "z":[["1",""],["2",""],["3",""],["3",""],["4",""],["5",""],["6",""],["5",""],["2",""],["3",""],["3",""],["5",""],["6",""],["5",""],["4","1"],["4","2"],["2","3"],["1","4"],["3","5"],["2","4"],["1","3"],["3","2"],["5","3"],["4","4"],["3","3"],["2","2"],["1","1"],["2","2"],["3","3"],["4","4"],["5","6"],["4","5"],["3","4"],["2","3"],["3","2"],["2","3"],["3","4"],["3","3"],["3","2"]],
+    "contours":{
+      "coloring": "fill",
+      "showlines": false,
+      "showlabels": true
+    },
+    "z":[[0, 10, 0], [10, 80, 20], [0, 40, 0]],
     "type":"contour"
   }],
   "layout":{
     "showlegend":false,
     "autosize":false,
     "height":400,
-    "width":400
+    "width":400,
+    "xaxis": {"range": [1, 2.5]},
+    "yaxis": {"range": [0.2, 1]}
   }
 }

test/image/baselines/contour_scatter.png

@@ -294,7 +294,10 @@
       ],
       "ncontours": 30,
       "showscale": false,
-      "type": "contour"
+      "type": "contour",
+      "contours": {
+        "showlabels": true
+      }
     },
     {
       "x": [