Forum Discussion
Help coloring Deneb heatmap
Doug7983, I see the issue. I had a rogue closed bracket in the data object that I missed. I deleted it and updated the above spec. Try it now.
"data": { "name": "dataset" ] //<-- Should not be there }Another great catch Doug7983. That's what I get for trying to rush through it 😆
gist{ "transform": [ {"calculate": "(month(datum['Date'])+1)", "as": "monthNum"}, { "calculate": "datum['monthNum'] + (datum['monthNum'] < 7 ? 6 : -6)", "as": "monthSort" }, { "calculate": "'FY ' + toString(year(datum['Date']) + (datum['monthSort'] <= 6 ? +1 : 0))", "as": "FY" } ], "facet": { "column": {"field": "FY", "title": null, "header": {"labelFontSize": 13}} }, "resolve": {"scale": {"x": "independent"}}, "spacing": {"column": 5}, "spec": { "width": {"step": 30}, "mark": {"type": "rect", "stroke": "white", "tooltip": true}, "encoding": { "x": { "field": "Date", "type": "ordinal", "title": null, "timeUnit": "month", "axis": { "domain": false, "ticks": false, "labels": true, "labelOpacity": 0.65, "orient": "top" }, "sort": {"field": "monthSort"} }, "y": { "field": "Category", "type": "nominal", "title": "", "axis": { "domain": false, "ticks": false, "labels": true, "labelOpacity": 0.65, "labelAngle": 0, "labelPadding": 5 } }, "tooltip": [ {"field": "Category", "type": "nominal"}, {"field": "Date", "type": "temporal"}, {"field": "Growth (MoYaM)", "type": "quantitative", "format": ".1%"}, {"field": "Growth (WDC)", "type": "quantitative", "format": ".1%"} ], "color": { "aggregate": "max", "field": "Growth (WDC)", "type": "quantitative", "title": "Growth (WDC)", "scale": {"domainMid": 0, "reverse": true, "scheme": "blueorange"}, "legend": { "titleBaseline": "bottom", "direction": "vertical", "format": ".1%", "orient": "right" } } } }, "data": { "name": "dataset" } }
Hey Doug7983, I'm only providing the values in the values array in the gist for example purposes. You can see that in the embedded spec (not the gist) I left that array out. Deneb assumes that you have named your data "dataset", and will receive the values dynamically from Power BI.
In the example that I provided, each row is independent from one another color-wise and thus has its own legend. That's why the lightest color for one row has a different minimum input domain (lowest value) than that of another row. If you were to go to the gist and comment out the following line:
"resolve": {"scale": {"color": "independent"}},
then the legend would no longer be independent for each row.
(color domains and legends are independent per row)
vs.
(color domain and legend are shared across entire dataset)
Forgive me, but I'm having trouble understanding. I'm confused about what you're trying to achieve because this:
My data has a range of -12.4% to 64.8%:
The deepest blue will always correspond to the highest value in the data set, regardless of row.
The deepest orange will always correspond to the lowest value in the data set, regardless of row.
The spectrum of color is applied such that a particular shade of blue, for example, will represent the same value, no matter where it appears. Same for shades of orange and everything in between.
seems to conflict with:
I’m new to Deneb and haven’t been able to figure out how to color this heatmap so that it is colored by row, or category, rather than as a whole:
<.png>
I want the rows to be color independently
For example, if the deepest blue will always correspond to the highest value in the data set regardless of row, the heatmap would not be colored independently.
Hey giammariam
You're absolutely right. Those are conflicting statements. I think maybe the missing piece is describing how the orange-blue diverging color palette is applied?
When I don't attempt to intervene in how Deneb applies pbiColorDivergent, Category 6 dominates the visual.
But that is far different from the original Tableau chart:
i think the difference may lie in how the colors are being applied. Here is a screenshot from Tableau:
Ah, this is very helpful! The midpoint of the input range is set to 0 in your Tableau screenshot. The scale in vega-lite is just taking into account the min/max values, so the midpoint here would be (max-min)/2. This would explain the color discrepancy. Let me play with it and see if I can get the scale to account for the 0 center threshold.