Screenshots and Recordings

Oct 13, 2025 by talynt.org 105 views

Introduction

Echarts is a powerful data visualization library used in various applications, including Superset, a popular data exploration and visualization platform. However, users have reported an issue with the y-axis sorting logic in Echarts heatmaps when there are empty cells. In this article, we will delve into the problem, explore the possible causes, and discuss potential solutions.

Bug Description

The issue was first reported by nicholaslimck in 31318. The problem occurs when creating a new Echarts heatmap chart with columns for X and Y axes, some cells in the heatmap should be empty. The expected behavior is that the y-axis should be sorted correctly, with values from 1 to 5 above 6. However, the actual behavior is that the sorting calculation skips y values where the metric is null, resulting in an incorrect sorting order.

How to Reproduce the Bug

To reproduce the bug, follow these steps:

Create a new Echarts heatmap chart.
Choose columns for X and Y axes, ensuring that some cells in the heatmap are empty.
Observe the resulting chart, which should display an incorrect y-axis sorting order.

Screenshots and Recordings

The following screenshots demonstrate the issue:

Incorrect y-axis sorting order: When there are empty values in the heatmap, the y-axis sorting order is incorrect.
More examples with empty values: Additional examples of the issue with empty values in the heatmap.

Superset Version

The issue was reported in Superset version 4.1.1.

Python Version

The issue was reported using Python version 3.9.

Node Version

The issue was reported using Node version 16.

Browser

The issue was reported using Chrome browser.

Additional Context

Interestingly, the legacy heatmap sorting works correctly, as shown in the following screenshot:

Legacy heatmap sorting works correctly: The legacy heatmap sorting order is correct, even with empty values in the heatmap.

Checklist

Before submitting this issue, we have:

Searched Superset docs and Slack for a solution to the problem.
Searched the GitHub issue tracker for a similar bug report.
Checked Superset's logs for errors and Python stacktraces.

Possible Causes

The possible causes of this issue are:

Incorrect sorting calculation: The sorting calculation may be skipping y values where the metric is null, resulting in an incorrect sorting order.
Inconsistent data handling: The data handling in Echarts heatmaps may be inconsistent, leading to incorrect sorting orders.

Potential Solutions

To resolve this issue, we can consider the following potential solutions:

Modify the sorting calculation: Modify the sorting calculation to include y values where the metric is null.
Improve data handling: Improve the data handling in Echarts heatmaps to ensure consistent sorting orders.

Conclusion

In conclusion, the Echarts heatmap y-axis sorting logic is not correct when there are empty cells. This issue has been reported in Superset version 4.1.1 and affects users who rely on Echarts heatmaps for data visualization. To resolve this issue, we can modify the sorting calculation or improve data handling in Echarts heatmaps. We hope that this article has provided valuable insights into the problem and potential solutions.

Recommendations

Based on our analysis, we recommend the following:

Upgrade to the latest Superset version: Upgrade to the latest Superset version to ensure that you have the latest fixes and features.
Use the legacy heatmap sorting: Use the legacy heatmap sorting if you need to ensure correct sorting orders.
Report any issues: Report any issues you encounter with Echarts heatmaps to the Superset community.

Future Work

To further improve Echarts heatmaps, we suggest the following:

Improve data handling: Improve data handling in Echarts heatmaps to ensure consistent sorting orders.
Enhance sorting calculation: Enhance the sorting calculation to include y values where the metric is null.
Provide more documentation: Provide more documentation on Echarts heatmaps, including examples and use cases.

Introduction

In our previous article, we discussed the issue with the Echarts heatmap y-axis sorting logic when there are empty cells. In this article, we will provide a Q&A section to address common questions and concerns related to this issue.

Q: What is the issue with the Echarts heatmap y-axis sorting logic?

A: The issue is that the y-axis sorting order is incorrect when there are empty cells in the heatmap. The expected behavior is that the y-axis should be sorted correctly, with values from 1 to 5 above 6. However, the actual behavior is that the sorting calculation skips y values where the metric is null, resulting in an incorrect sorting order.

Q: How can I reproduce the bug?

A: To reproduce the bug, follow these steps:

Create a new Echarts heatmap chart.
Choose columns for X and Y axes, ensuring that some cells in the heatmap are empty.
Observe the resulting chart, which should display an incorrect y-axis sorting order.

Q: What are the possible causes of this issue?

A: The possible causes of this issue are:

Incorrect sorting calculation: The sorting calculation may be skipping y values where the metric is null, resulting in an incorrect sorting order.
Inconsistent data handling: The data handling in Echarts heatmaps may be inconsistent, leading to incorrect sorting orders.

Q: How can I resolve this issue?

A: To resolve this issue, you can consider the following potential solutions:

Modify the sorting calculation: Modify the sorting calculation to include y values where the metric is null.
Improve data handling: Improve the data handling in Echarts heatmaps to ensure consistent sorting orders.

Q: What are the recommended solutions for this issue?

A: Based on our analysis, we recommend the following:

Upgrade to the latest Superset version: Upgrade to the latest Superset version to ensure that you have the latest fixes and features.
Use the legacy heatmap sorting: Use the legacy heatmap sorting if you need to ensure correct sorting orders.
Report any issues: Report any issues you encounter with Echarts heatmaps to the Superset community.

Q: What are the future work recommendations for this issue?

A: To further improve Echarts heatmaps, we suggest the following:

Improve data handling: Improve data handling in Echarts heatmaps to ensure consistent sorting orders.
Enhance sorting calculation: Enhance the sorting calculation to include y values where the metric is null.
Provide more documentation: Provide more documentation on Echarts heatmaps, including examples and use cases.

Q: Can I get more information about the issue?

A: Yes, you can get more information about the issue by:

Checking the GitHub issue tracker: Check the GitHub issue tracker for similar bug reports.
Searching Superset docs and Slack: Search Superset docs and Slack for a solution to the problem.
Contacting the Superset community: Contact the Superset community for more information and support.

Conclusion

In conclusion, the Echarts heatmap y-axis sorting logic is not correct when there are empty cells. This issue has been reported in Superset version 4.1.1 and affects users who rely on Echarts heatmaps for data visualization. We hope that this Q&A article has provided valuable insights into the problem and potential solutions. If you have any further questions or concerns, please don't hesitate to contact us.