Chart - sum Y column values rather than displaying last Y value

[akc2267]

Issue Summary

Chrome Mac OS. When creating Pie charts, I noticed that the fractional representation is accurate; however, the hover displays the last Y value rather than summing up all Y values for the given X value. This causes hover values that make absolutely no sense.

Steps to Reproduce

1. Create a query that results in a table with 1 numerical value Y column (like population) and 2+ possible X columns (like City & State).
2. Create a pie chart visualization with the larger X column (State) and the Y column (population).
3. Notice that while the pie chart properly displays the fractional representation of the X values, it only displays the last row of the respective Y column for that X value. Instead, this should displayed the summed up value. (State should show the summed population of all of its cities, rather than the population of the last city in the table)

Technical details:

• Redash Version: 7.0.0+b18042 (4a978ba)
• Browser/OS: Chrome/MacOS
• How did you install Redash: The company that employs me is running redash in a self-managed datacenter

[kravets-levko]

Hi @akc2267! There is a related discussion on our forum where we explain why the things work in this way and what you can use as a workaround: https://discuss.redash.io/t/wrong-label-view/5237

[akc2267]

Thank you for the quick response! Unfortunately that solution does not work for my use case. My dashboards are getting aggravatingly slow, as I have to create separate queries for each pie chart. My specific use case is dividing out costs across my Company's various orgs. These are represented in 6 layers (tier 1-6 for example). So in order to have accurate pie charts for all orgs, I need 6 queries to group by the 6 individual tiers. I would much rather have just 1 query that groups by all 6 tiers and displays the most granular dollar amount attributable to the lowest org. I could then attach 6 pie charts to this single query, with each pie chart using a different org tier as the X value and dollars as the Y value. This would massively reduce the time it takes to load my dashboard, especially considering I have filters to single out any specific tier or org.

[akc2267]

@kravets-levko, If I made a merge request to fix this, would it be reviewed?

I'm trying to reason with the current format and I just don't see how it could be considered an intended default behavior. Pie chart labels should match their fractional allocations always.

[kravets-levko]

Most likely we'll fix this one day, but no any estimates for now. If you want to submit a fix - you're welcome 🙂

[akc2267]

Just a note that this bug affects all chart data labels, not just pie charts

[akc2267]

@kravets-levko, I've found the error in the code:

prepareSeries(series, options, additionalOptions)
-the mapreduce functions result in only the last row (y) for each (x) actually being used.
-this exists in both preparePieData.js and prepeareDefaultData.js

I think the best way to fix this while keeping the general code structure intact is by creating a Dictionary, aggregating y values for each x. I am attempting to do this now.

But, I have a general question: why did y'all decide to create your own labels versus using Plotly's built in labels? Surely this is degrading your performance as both plotly and redash are calculating these values (and plotly currently does it incorrectly)
EDIT: it seems that plotly provides the percentage values. Maybe it doesn't provide the aggregated y values?

[akc2267]

Note that the percentage values between the pie chart and the hover label are wildly different. Also note that the population value in the hover label only shows the population for one city in all of california