LUE

EGU 2026 session about high-performance computation in the geosciences

Computational Geography group — Mon, 20 Oct 2025 10:06:42 GMT

Together with colleagues from five European research institutes we have submitted a session proposal for the EGU 2026 General Assembly in Vienna, Austria. The session is about high-performance computation in the geosciences. We are happy to report that the session has been accepted into the programme as part of the programme group Earth & Space Science Informatics.

You can find more information about this session on the EGU26 home page.

If your work fits within its scope, then we invite you to submit an abstract to this session. Abstract submission will be open from 22 Oct 2025 to 15 Jan 2026, 13:00 CET. We look forward to meeting you in Vienna in May 2026!

Support for Python 3.14

Computational Geography group — Mon, 08 Sep 2025 10:04:00 GMT

LUE's Python package can be use used with Python versions greater than 3.9, including the upcoming Python version 3.14. We maintain easy to install Conda packages to get you started quickly with LUE. Information about all available LUE Conda packages can be found on the LUE Conda package page. More information about how to install and use LUE can be found in the documentation pages.

Release of version 0.3.10

Computational Geography group — Tue, 12 Aug 2025 06:26:03 GMT

We have released LUE version 0.3.10, containing the result of 8 months of development. Details can be found in the Releases page in the manual.

A lot has happened which is not visible to end-users. Changes most relevant to them are:

New operations: resample
New lue.pcraster Python subpackage operation wrappers: mapnormal, mapuniform
Updated the documentation:
- Quick start for Python users
- How to cite LUE
- FAQ
Add overloads to reclassify operation returning integral arrays
Support Python 3.13

See the Community page for ways to get in touch with us and stay up to date about LUE.

Install the LUE Conda package (screencast)

Computational Geography group — Tue, 10 Dec 2024 15:13:55 GMT

Release of version 0.3.9

Computational Geography group — Thu, 05 Dec 2024 13:05:23 GMT

After more than a year, we released a new version of LUE. A lot has happened since the previous release. Details can be found in the Releases page in the manual. The sharp reader may notice that the release of version 0.3.8 hasn't been announced in the past. We skipped it due to issues with the Conda package build process. That is all fixed now, but that does mean that the set of changes made since the previous officially released version (0.3.7) is the combination of those made for both the 0.3.8 release and the 0.3.9 release.

The detailed list of changes contains too much detail for the LUE end-user. Here is the list of changes most relevant to them:

Added new operations, e.g.: clump, log10, negate, normal, round_down, round_off, round_up, sqr, square
cast now supports casting from floating point element types to integral element types
Updated the documentation.
Added support for default partition shapes. These are used when no partition shape is passed to commands and operations that need one. For best performance a good partition shape must be determined experimentally, but to get started a default one can be used.
Added the lue_calculate.py command for one-off computations from the command-line
Improved the lue.pcraster Python sub-package. For most operations in PCRaster we now have LUE equivalents. Porting existing PCRaster models to use LUE has never been easier.
Improved support for asynchronously computed scalar values. Most operations accepting a regular scalar value have been overloaded to also accept ascynhronously computed scalar values.
Added support for NumPy-2

See the Community page for ways to get in touch with us and stay up to date about LUE.

lue_scalability for scalability experiments

Computational Geography group — Wed, 06 Nov 2024 13:01:38 GMT

One of the goals for developing LUE is to research scalable algorithms for spatial analysis. A LUE computation should make good use of additional hardware, to make computations finish faster, or to make larger computations feasible.

Scalability experiments involve executing a certain computation many times, while varying the amount of hardware and/or data, and recording the latencies involved. Afterwards, all recorded latencies have to be aggregated, statistics computed, and further postprocessed to end up with scalability plots showing the efficiencies.

The example below shows the results of a strong scalability experiment of a LUE version of Conway's Game of Life. The second plot shows that using 12 CPU cores instead of one, speeds up the model almost 10 times.

To make it convenient to perform scalability experiments, we have developed the lue_scalability.py command. This command removes much of the administrative and practical burdens of performing such experiments. For more information, see the manual about scalability.

lue_calculate for one-off computations

Computational Geography group — Mon, 25 Sep 2023 14:49:10 GMT

Sometimes you may want to quickly compute some new result based on existing datasets, maybe just for visualization purposes, or to test an idea. Creating a new C++ program or Python script may feel like a lot of work for such a simple task. For that we have created the lue_calculate command. It allows you to execute an assignment statement which you pass on the command-line, and it will do everything needed to finish the computations as quickly as possible. By default, lue_calculate will use all CPU cores available, but this can be configured by passing additional arguments. Here are two examples:

lue_calculate 'slope.tif = slope("$MY_DATA/elevation.tif", 100.0)'
lue_calculate 'flux, state = accu_threshold("flow_direction", "material", "threshold")'

As you can see, the command supports expanding environment variables (on Windows, %VARIABLE% is also expanded), multiple return values, and default file extensions. Nested expressions are also supported. The one limitation is that only a single assignment statement can be passed to the command. If you need more, then you can still write a C++ or Python program, of course.

The lue_calculate command will be part of the upcoming 0.3.8 release.

For more details, execute lue_calculate --help and see the LUE documentation.

First hands-on LUE short course given

Computational Geography group — Wed, 06 Sep 2023 09:29:59 GMT

At June 29 we organized the first hands-on LUE short course. In about three hours the course participants learned everything that is needed to get started with using LUE to build scalable simulation models.

In turn, the following topics where handled:

Introduction of the LUE modelling framework
How to execute LUE models
The hydrological case-study model
Measuring performance and scalability
The factors influencing performance and scalability
Calculating the scalability of the case-study model
Relation LUE vs PCRaster, and upcoming developments

The group of course participants consisted of people working at both research institutes and private companies. Some of them where in the room with us and some where joining online.

We think the course was a success. Everybody learnt a lot, including us.

We will be organizing more LUE courses over time. If you are interested in joining us, then do let us know (lue@computationalgeography.org), and we will notify you once we picked a date.

Hands-on LUE short course

Computational Geography group — Thu, 25 May 2023 13:12:12 GMT

Building scalable spatial simulation models the easy way

We are organizing a short introductory course about using LUE to develop scalable numerical spatial simulation models. At June 29, between 14:00-17:00 we will explain everything you need to get started with using LUE yourself. We will cover at least the following topics:

An overview of how LUE works internally, without the details.
Installing LUE. Bring your own device!
Develop a simple model using the LUE Python binding. Verify that all the CPU cores are being used.
Q&A. Ask us anything.
Drinks.

The course will be held at our institute at the Utrecht Science Park, the Netherlands, but it will be possible for people to join online as well. Participation is free of charge.

In case you are interested in participating in this course, then please let us know (lue@computationalgeography.org), with answers to the following questions:

Do you prefer to join us on-site or online?
Any suggestions for the course? For example: topics we should not forget to cover, or a case you are particularly interested in.

We would be grateful if you could extend this invitation to any of your colleagues who might be interested in learning about LUE.

AMT/HPX workshop EGU 2023

Computational Geography group — Mon, 07 Nov 2022 13:29:22 GMT

The Computational Geography group is organizing a workshop about parallel programming using asynchronous many-tasks (AMT) and the HPX C++ library during the EGU General Assembly 2023 in Vienna. AMT/HPX is used in the implementation of the LUE framework. During this workshop we will introduce this approach and illustrate how it is used in LUE.

This workshop is especially relevant for C++ software developers interested in developing scalable software. Knowing about AMT/HPX is not required for LUE users, but it might be interesting for them too.

For more information, see the associated short course page on the EGU23 website.