Column Axis Is Misaligned By Colorbar While Making Subplot From Xarray

Introduction

When working with xarray and hvplot to create subplots, a common issue arises when using a colorbar. The column axis labels become misaligned when the colorbar is present. This problem can be frustrating, especially when trying to create visually appealing and informative plots. In this article, we will delve into the issue, explore the expected and observed behavior, and provide a minimal, self-contained example code that reproduces the problem.

Expected Behavior and Observed Behavior

Expected Behavior

When displaying multiple images or contour plots using hvplot with the row and col parameters, the column axis labels should align properly with the image plots, regardless of the colorbar settings. This means that the column axis labels should be in sync with the image plots, providing a clear and consistent visual representation of the data.

Observed Behavior

However, when colorbar=True, the column axis labels become misaligned due to the presence of the colorbar. This means that the column axis labels are not in sync with the image plots, creating a visual inconsistency. On the other hand, when colorbar=False, the column axis labels align correctly, indicating that the issue is specifically related to the colorbar.

Minimal, Self-Contained Example Code

The following code snippet demonstrates the issue:

import hvplot.xarray
import xarray as xr
import numpy as np

da = xr.DataArray(
    np.arange(150).T.reshape(2,3,5,5),
    coords={"x": np.arange(5), "y": np.arange(5),'z':np.arange(3),'t':np.arange(2)},
    dims=("t", "z","y","x"),
)

plot_da = da.hvplot.image(x='x',y='y',
                row='z',
                col='t',
                colorbar=True,
                shared_axes=True,
                cmap='plasma',
                width=1200,
                height=800
                )

plot_da

This code creates a 2D DataArray with 2 time steps, 3 z levels, 5 x coordinates, and 5 y coordinates. It then uses hvplot to create an image plot with the specified parameters, including colorbar=True.

Stack Traceback and/or Browser JavaScript Console Output

No error messages are produced, as this is a visual alignment issue.

Screenshots or Screencasts of the Bug in Action

The following screenshots demonstrate the issue:

Software Version Info

The following software versions were used to reproduce the issue:

• OS: Windows 11
• Python: 3.12
• hvplot: 0.11.2
• xarray: 2025.4.0
• jupyter_bokeh: 4.0.5

Conclusion

In conclusion, the column axis misalignment issue with colorbar in xarray subplot is a common problem that can be frustrating to resolve. By understanding the expected and observed behavior, as well as providing a minimal, self-contained example code, we can better diagnose and address this issue. We hope that this article has provided valuable insights and assistance in resolving this problem.

Troubleshooting and Workarounds

To troubleshoot and resolve this issue, you can try the following workarounds:

1. Disable the colorbar: Set colorbar=False to see if the column axis labels align correctly.
2. Adjust the plot layout: Experiment with different plot layouts, such as changing the row and column parameters or using a different subplot configuration.
3. Use a different visualization library: Consider using a different visualization library, such as Matplotlib or Seaborn, to create the plot.
4. Update the software versions: Ensure that you are using the latest versions of the software, including hvplot, xarray, and jupyter_bokeh.

Q: What is the column axis misalignment issue with colorbar in xarray subplot?

A: The column axis misalignment issue with colorbar in xarray subplot is a problem that occurs when using hvplot to create a subplot with a colorbar. The column axis labels become misaligned due to the presence of the colorbar, making it difficult to create a visually appealing and informative plot.

Q: What are the expected and observed behaviors of the column axis misalignment issue?

A: The expected behavior is that the column axis labels should align properly with the image plots, regardless of the colorbar settings. However, the observed behavior is that the column axis labels become misaligned when colorbar=True, and align correctly when colorbar=False.

Q: What is the minimal, self-contained example code that reproduces the issue?

A: The following code snippet demonstrates the issue:

import hvplot.xarray
import xarray as xr
import numpy as np

da = xr.DataArray(
    np.arange(150).T.reshape(2,3,5,5),
    coords={"x": np.arange(5), "y": np.arange(5),'z':np.arange(3),'t':np.arange(2)},
    dims=("t", "z","y","x"),
)

plot_da = da.hvplot.image(x='x',y='y',
                row='z',
                col='t',
                colorbar=True,
                shared_axes=True,
                cmap='plasma',
                width=1200,
                height=800
                )

plot_da

This code creates a 2D DataArray with 2 time steps, 3 z levels, 5 x coordinates, and 5 y coordinates. It then uses hvplot to create an image plot with the specified parameters, including colorbar=True.

Q: What are the software versions used to reproduce the issue?

A: The following software versions were used to reproduce the issue:

• OS: Windows 11
• Python: 3.12
• hvplot: 0.11.2
• xarray: 2025.4.0
• jupyter_bokeh: 4.0.5

Q: What are some troubleshooting and workarounds for the column axis misalignment issue?

A: To troubleshoot and resolve this issue, you can try the following workarounds:

1. Disable the colorbar: Set colorbar=False to see if the column axis labels align correctly.
2. Adjust the plot layout: Experiment with different plot layouts, such as changing the row and column parameters or using a different subplot configuration.
3. Use a different visualization library: Consider using a different visualization library, such as Matplotlib or Seaborn, to create the plot.
4. Update the software versions: Ensure that you are using the latest versions of the software, including hvplot, xarray, and jupyter_bokeh.

Q: How can I prevent the column axis misalignment issue in the future?

A: To prevent the column axis misalignment in the future, you can try the following:

1. Use a consistent plot layout: Ensure that the plot layout is consistent across all subplots.
2. Avoid using the colorbar: If possible, avoid using the colorbar or use a different visualization library that does not have this issue.
3. Update the software versions: Regularly update the software versions to ensure that you have the latest features and bug fixes.
4. Experiment with different plot configurations: Experiment with different plot configurations to find one that works for your specific use case.

By following these tips and workarounds, you can prevent the column axis misalignment issue and create visually appealing and informative plots using hvplot and xarray.