Adding an option for line_interpolation in line chart

panoramix/forms.py

@@ -126,6 +126,13 @@ class FormFactory(object):
                 choices=[(s, s) for s in ['random', 'flat', 'square']],
                 default="random",
                 description="Rotation to apply to words in the cloud"),
+            'line_interpolation': SelectField(
+                "Line Interpolation",
+                choices=[(s, s) for s in [
+                    'linear', 'basis', 'cardinal', 'monotone',
+                    'step-before', 'step-after']],
+                default='linear',
+                description="Line interpolation as defined by d3.js"),
             'code': TextAreaField("Code", description="Put your code here"),
             'size_from': TextField(
                 "Font Size From",

panoramix/static/widgets/viz_nvd3.js

@@ -38,9 +38,11 @@ function viz_nvd3(token_name, json_callback) {
               .tickFormat(function (d) {return tickMultiFormat(UTC(new Date(d))); })
               .tickValues([]);
             chart.y2Axis.tickFormat(d3.format('.3s'));
+            console.log(viz.form_data.line_interpolation);
           } else {
             var chart = nv.models.lineChart()
           }
+          chart.interpolate(viz.form_data.line_interpolation);
           chart.xScale(d3.time.scale());
           chart.xAxis
             .showMaxMin(false)

panoramix/viz.py

@@ -387,7 +387,7 @@ class NVD3TimeSeriesViz(NVD3Viz):
         'metrics',
         'groupby', 'limit',
         ('rolling_type', 'rolling_periods'),
-        ('num_period_compare', None),
+        ('num_period_compare', 'line_interpolation'),
         ('show_brush', 'show_legend'),
         ('rich_tooltip', 'y_axis_zero'),
         ('y_log_scale', 'contribution')