How to Element-Wise Apply a Custom Function Using Xarray in Python

Discover how to effectively apply a custom function element-wise to an xarray DataArray in Python, even when working with non-vectorized functions.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Apply function element-wise

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Element-Wise Apply a Custom Function Using Xarray in Python

If you've ever found yourself needing to apply a custom, non-vectorized function to each element of an xarray DataArray, you may have encountered some pitfalls along the way. This post will guide you through the problem and present a step-by-step solution that enables you to accomplish this efficiently.

The Problem

Example Scenario

Here's a basic example to illustrate the situation:

[[See Video to Reveal this Text or Code Snippet]]

As noted, the following method doesn't provide the intended result because custom_function is applied to the whole array:

[[See Video to Reveal this Text or Code Snippet]]

The Solution

Step-by-Step Solution

Define Your Function: Ensure your custom function is defined to take a scalar input and return a scalar output, just as you would like it to behave element-wise.

Implementation Example:

Here's how you can correctly set it up:

[[See Video to Reveal this Text or Code Snippet]]

Expected Output

When you run the above code, you will get:

[[See Video to Reveal this Text or Code Snippet]]

Explanation

Conclusion

With this knowledge, you can confidently tackle the challenge of applying custom functions in xarray and enhance your data manipulation skills in Python.