Merge pull request #75 from WarwickCIM/second-attempt-y-axis-trouble

Share y axis between "density" and "colours used" plot, but not main plot

tests/expected_meta_hist_choropleth.json

@@ -363743,6 +363743,10 @@
             "maxbins": 100
           },
           "field": "pct_estimate",
+          "scale": {
+            "nice": true,
+            "zero": false
+          },
           "title": "",
           "type": "quantitative"
         }
@@ -363801,6 +363805,7 @@
           },
           "field": "y",
           "scale": {
+            "nice": true,
             "zero": false
           },
           "title": "",
@@ -363861,10 +363866,5 @@
       "title": "test_choropleth",
       "width": 500
     }
-  ],
-  "resolve": {
-    "scale": {
-      "y": "shared"
-    }
-  }
+  ]
 }

tests/expected_meta_hist_choropleth_extent.json

@@ -363747,6 +363747,13 @@
             "maxbins": 100
           },
           "field": "pct_estimate",
+          "scale": {
+            "domain": [
+              0,
+              100
+            ],
+            "nice": true
+          },
           "title": "",
           "type": "quantitative"
         }
@@ -363808,6 +363815,13 @@
             "orient": "right"
           },
           "field": "y",
+          "scale": {
+            "domain": [
+              0,
+              100
+            ],
+            "nice": true
+          },
           "title": "",
           "type": "quantitative"
         },
@@ -363874,10 +363888,5 @@
       "title": "test_choropleth_extent",
       "width": 500
     }
-  ],
-  "resolve": {
-    "scale": {
-      "y": "shared"
-    }
-  }
+  ]
 }

tests/expected_meta_hist_scatterplot.json

@@ -57721,6 +57721,7 @@
           },
           "field": "y",
           "scale": {
+            "nice": true,
             "zero": false
           },
           "title": "",
@@ -57774,10 +57775,5 @@
       "mark": "circle",
       "title": "test_scatterplot"
     }
-  ],
-  "resolve": {
-    "scale": {
-      "y": "shared"
-    }
-  }
+  ]
 }

tests/expected_meta_hist_scatterplot_bin_False.json

@@ -57715,9 +57715,6 @@
             "orient": "right"
           },
           "field": "y",
-          "scale": {
-            "zero": false
-          },
           "title": "",
           "type": "quantitative"
         },
@@ -57754,10 +57751,5 @@
       "mark": "circle",
       "title": "test_scatterplot_bin_False"
     }
-  ],
-  "resolve": {
-    "scale": {
-      "y": "shared"
-    }
-  }
+  ]
 }

ways_py/ways.py

@@ -24,9 +24,12 @@ def field(src: alt.Chart) -> str:
     @staticmethod
     def density_chart(src: alt.Chart) -> alt.Chart:
         if src.encoding.color.bin and is_defined(src.encoding.color.bin.extent):
-            bin = alt.Bin(maxbins=100, extent=src.encoding.color.bin.extent)
+            extent = src.encoding.color.bin.extent
+            bin = alt.Bin(maxbins=100, extent=extent)
+            y_scale = alt.Scale(domain=extent, nice=True)
         else:
             bin = alt.Bin(maxbins=100)
+            y_scale = alt.Scale(zero=False, nice=True)
         ys = src.data[Ways.field(src)]  # assume src.data array-like in an appropriate way
         y_min, y_max = min(ys), max(ys)
         # tickCount/tickMinStep Axis properties are ignored (perhaps because we specify bins), so hard code
@@ -35,6 +38,7 @@ def density_chart(src: alt.Chart) -> alt.Chart:
             bin=bin,
             axis=alt.Axis(orient='left', grid=False, values=sorted([0, 50] + [y_min, y_max])),
             title="",
+            scale=y_scale
         )
         x_axis = alt.X(
             'sum(proportion):Q',
@@ -53,13 +57,18 @@ def density_chart(src: alt.Chart) -> alt.Chart:
     def used_colours(src: alt.Chart) -> alt.Chart:
         y_axis = alt.Axis(orient='right', grid=False)
         x_axis = alt.Axis(labels=False, tickSize=0, grid=False, titleAngle=270, titleAlign='right')
+        if src.encoding.color.bin and is_defined(src.encoding.color.bin.extent):
+            extent = src.encoding.color.bin.extent
+            y_scale = alt.Scale(domain=extent, nice=True)
+        else:
+            y_scale = alt.Scale(zero=False, nice=True)
         if src.encoding.color.bin:
             chart = alt.Chart(src.data) \
                 .mark_rect() \
                 .transform_bin(as_=['y', 'y2'], bin=src.encoding.color.bin, field=Ways.field(src)) \
                 .transform_calculate(x='5') \
                 .encode(
-                    y=alt.Y('y:Q', axis=y_axis, title=""),
+                    y=alt.Y('y:Q', axis=y_axis, title="", scale=y_scale),
                     y2='y2:Q',
                     x=alt.X('x:Q', sort='descending', axis=x_axis, title="colours used")
                 )  # noqa: E123
@@ -92,7 +101,7 @@ def altair_meta_hist(src: alt.Chart) -> alt.Chart:
         if not is_defined(src.encoding.color.bin):
             raise Exception("Can only apply decorator to chart with color.bin defined.")
 
-        meta_chart: alt.Chart = (Ways.density_chart(src) | Ways.used_colours(src)).resolve_scale(y='shared')
+        meta_chart: alt.Chart = (Ways.density_chart(src) | Ways.used_colours(src))
         return (meta_chart | src) \
             .configure_view(strokeWidth=0) \
             .configure_concat(spacing=5)