Claus Haslauer's Website

Nanopixel Programming

2026-01-23T17:50:07.088472+01:00

With good intentions for ~Christmas~ our upcoming “Rainbow” project, I bought a Adafruit 12mm Diffuse Thin Digital RGB LED Pixel (strand of 25). I wasn’t sure where to start, it took a bit longer than I had anticipated (d’oh). And today I finally found some time to sit down. What did I learn?

Most importantly, it works well with adafruit_ws2801.

I did search quite a bit, but the adafruit overview turned out to be pretty great! This means I ended up using CircuitPython and not micropython. I am too much of a newbie to understand what that really means.
I did not spend enough time with the Raspberry 4 I started with. Now it works on a Raspery Pico (old version, no “2”).
The wiring that ended up working for me, is very similar to the one displayed here, including the power connection, except the pins on the pico are connected like this:

position cable color ID corresponding code

0 green GPIO0 oclock = board.GP0

1 yellow GPIO1 odata = board.GP1

2 blue GND
I did install the latest version of Adafruit CircuitPython, but was able to transfer the 10.0.3 version’s *.uf2 file to the pico’s thumb drive (bootsel pushed while plugging usb cable in) only after I had tried unsuccessfully with two other cables…
Similarly, I was unable to transfer anything (single file or entire lib directory) from the adafruit/Adafruit_CircuitPython_Bundle, version Dec 31, 2025; 10.xvia the finder on OSX. It did work in terminal using cp. What year are we living in?
I did not install other python versions
adafruit’s sample code does work, except for the adaptions to the GP0 und GP1 noted in the table above.
in CicuitPython, it seems the file that contains the code that is run when the pico is turned on but not connected to a computer, should not be called main.py, but code.py.

position	cable color	ID	corresponding code
0	green	GPIO0	`oclock = board.GP0`
1	yellow	GPIO1	`odata = board.GP1`
2	blue	GND

To Dos

in the appendix of the “Raspberry Pi Pico-series Python SDK” (p.45), there is a Section including code sample for “Using PIO to drive a set of NeoPixel Ring (WS2812 LEDs)”, which seems a bit more hard coded, and I am curious how that would transfer to a WS2801.
I did try to get some support from Claude in the process. Let’s say with some mixed results. For the wiring it was not of any help, essentially I used the interactiv prompt in Thonny to figure out what attributes board has, and tried D0 and D1, eventually in the correct order. Claude did provide some sample codes that look good, but haven’t tested those yet. Also, at the moment I am running this with Sonnet 4.5. I’ve read some good feedback for Opus 4.5 has some good feedback. Maybe I should also consider GitHub CoPilot. Keep in mind, these tools have their issues with language

Frequencies of words used change after release of Chat-GPT; [source: bsky](https://bsky.app/profile/rosiecollington.bsky.social/post/3lykfqmzd5c2b)).

while this might be interesting for my WS2801, unfortunately, it does not seem to be a neopixel 5).

New Things

2026-01-02T09:56:39.656855+01:00

monks in the monastery of St. Gallen have been singing for a long time. The lead singer even developed a notation so he could remember the songs. Not only the text, but the relative movement of the melody, however not absolute notes. This was all in a single tune (mono-phonic).

When we visited St. Gallen this summer, we also saw the first notation of polyphonic sheet music (see picture from movie below). It looked very nicely. Each voice had its quarter on a double-page. Our guide told us how the monks were resistant against picking up the “new way” of singing. It was even considered bad.

First four-part sheet music used in the monastery St. Gallen ([source](https://www.youtube.com/watch?v=zb6FXynLhzs)).

Supposedly, it took one hundred years for the monks to pick up four-part polyphonic singing.

I am not a musical expert but there are some awesome polyphonic tunes, but

the beginning of Ronja Räubertochter: Ronja Räubertochter / Ronja Rövardotter (1984) Soundtrack: Intro - YouTube
I have fond memories of a concert of the Smashing Pumpkins about in 2007 in Colmar, when the audience sang along in six-way singing
The Paghjella, the traditional polyphonic singing in Corse, which according to Wikipedia has been developing from the Gregorian chants

The Köln Concert

2025-12-30T10:28:50.364802+01:00

I heard about this Jazz story only yesterday. It’s also a great Christmas story. On 24-January-1975, the young pianist Keith Jarrett was to play in the opera house in Cologne. The concert was organized by the 18-year-old concert promoter Vera Brandes, sold out, and about to start at 11:30pm. Things have started to go off the rails at least from early afternoon on. The pianist arrived by car from an earlier concert in Switzerland, was tired, hungry, and felt under the weather. His food did not arrive on time. Even worse, only later that Friday evening, he realized that the piano on stage was not the concert piano he had asked for, but a shabby, out of tune mini piano used for rehearsals. Some tuners managed to improve its condition a bit. Note it was Friday evening, and no cell phones existed in 1975. Jarrett was supposedly already back in his car, ready to leave after announcing he would not play, when Vera Brandes opened the passenger door and supposedly said something like: “please play, otherwise I am done”. Jarrett’s answer is somewhat legendary: “Okay, I’ll play. But never forget – just for you!”. The tone-engineers had already setup the recording equipment, and started to record anyways. They did not expect a great recording with that piano. Were they ever wrong. It turned out to be the most sold Jazz-Solo recording and the most sold piano solo recording. It is known now as “The Köln Concert”. Jarrett improvised around the notes G D C G A D, which supposedly form the melody of the bell that announces the beginning of a concert in the Köln opera house.

Why is this a great christmas story? — The tools are only secondary. If you are in the zone, interesting things will emerge.

Poster advertising the Jarrett Cologne Concert.

EGU26 Geostatistics Session

2025-12-26T10:58:32.815794+01:00

We invite submissions to our EGU26 session HS3.4: Advanced Geostatistical Methods and Uncertainty Analysis in Hydrological and Environmental Sciences

Abstract submission is possible until 15 January 2026.

For details see: https://www.egu26.eu/session/56817

Download PDF-poster

Convenors: Claus Haslauer, Mathieu Gravey, Emmanouil Varouchakis, Carolina Guardiola-Albert

Poster for EGU26 Geostatistics Session.

In recent years, the field of geostatistics has seen significant advancements. These methods are fundamental in understanding spatially and temporally variable hydrological and environmental processes, which are vital for risk assessment, input for other models, and management of extreme events like floods and droughts. This session aims to provide a comprehensive platform for researchers to present and discuss innovative applications and methodologies of geostatistics and spatio-temporal analysis in hydrology and related fields. The focus will be on traditional approaches and the assessment of uncertainties, whereas Machine Learning approaches have their specific and other dedicated sessions.

We invite contributions that address the following topics (but not limited to):

Spatio-temporal Analysis of Hydrological and Environmental Anomalies:
- Methods for detecting and analyzing large-scale anomalies in hydrological and environmental data.
- Techniques to manage and predict extreme events based on spatio-temporal patterns.
Innovative Geostatistical Applications:
- Advances in spatial and spatio-temporal modeling.
- Applications in spatial reasoning and data mining.
- Reduced computational complexity methods suitable for large-scale problems.
Geostatistical Methods for Hydrological Extremes:
- Techniques for analyzing the dynamics of natural events, such as floods, droughts, and morphological changes.
- Utilization of copulas and other statistical tools to identify spatio-temporal relationships.
Optimization and Generalization of Spatial Models:
- Approaches to optimize monitoring networks and spatial models.
- Techniques for predicting regions with limited or unobserved data e.g., using physical-based model simulations or using secondary variables.
Uncertainty Assessment in Geostatistics:
- Methods for characterizing and managing uncertainties in spatial data.
- Applications of Bayesian Geostatistical Analysis and Generalized Extreme Value Distributions.
Spatial and Spatio-temporal Covariance Analysis:
- Exploring links between hydrological variables and extremes through covariance analysis.
- Applications of Gaussian and non-Gaussian models in spatial analysis and prediction.

resurrection

2025-12-21T21:21:59.326980+01:00

I finally installed from scratch the latest pelican version. I had this weird problem that the http://... version did get displayed correctly whereas the https://... version of my site did not get displayed correctly (without proper css). I had googled and did not want to bother, but it led to me doing rather other things then paying attention to this site. Now, today I setup Claude, and for an interesting twist of fate, the first question I asked was

with "http" my own website on, pelican appears correctly, if I use "https" it seems like the wrong stylesheet is used. How do I tell it to use the correct stylesheet every time

You will have noticed that I am a novice at writing prompts. However, it gave me the response that I should use something like a relative URL path

SITEURL = '//yourdomain.com'  # Note the // without http: or https:

This seemed so trivial and logical that I did not even bother to test, but I went straight to installing the latest pelican verision. It has the benefit of no more version conflict errors with python and the handling of themes and plugins seems improved. Over a year ago, I declared I would stick with pelican. New development has been happening, albeit at slow pace. Well, I am still here ;-)

archival digg

2024-09-09T21:44:19.905437+02:00

I updated this site to the latest version of pelican (4.9.1). The old setup I had, to convert jupyter notebook files to html is not working anymore, because of something in nbconvert (see here and here). I could have tried mkdocs and mkdocs-jupyter. I could have attempted something slick like Brett Terpstra. However, I decided that this webpage is not hosting too many jupyter notebooks (for now). So I stuck with plain pelican for now. Maybe this is not for eternity. But what is?

The html renders of the notebooks can be found here:

In the meantime, the novel version of pelican compiles reasonably fast this site, so I will stick with it for a little while longer ;-)

low order moments

2022-01-24T09:12:00+01:00

It’s not only that with a few parameter, one can model an elephant and wiggle its tail. It’s also that lower moments are not unique and can model a dinosaur!

presentations at AGU2019

2019-12-03T17:12:00+01:00

The AGU Fall Meeting is back in San Francisco, I will be back in San Francisco. Looking forward to see you there!

Authors	Title	Date	Time	Location	Session
Samuel Scherrer, Claus P Haslauer, Holger Class, Oliver Trötschler, Jürgen Braun, Norbert Klass	H11K-1655: Heat Transport in the Shallow Subsurface (Numerically and Experimentally)	Monday, 9 December 2019	8:00-12:20	H11K-1655	H11K - Developments in Geothermal Energy II Posters
Bo Xiao, Claus P Haslauer, Geoffrey C Bohling, András Bárdossy	H21L-1914: Non-Gaussian Simulation: Including Multiple Types of Information at Non-colocated Locations	Tuesday, 10 December 2019	8:00-12:20	154 AB	H21L: Heterogeneity, Upscaling, and Uncertainty Quantification in Subsurface Flow and Transport II Posters
Thomas Bierbaum, Daniela Schmid, Norbert Klaas, Claus P Haslauer, Jürgen Braun, Frank Thomas Lange and Marco Scheurer	H21I-1845: Testing PFAS-Immobilization	Tuesday, 10 December 2019	8:00-12:20	H21I-1845	H21I - Advances in Subsurface Contaminant Transport and Remediation: Addressing Current and Emerging Challenges IV Posters

Still in the Yukon

2019-11-08T09:50:00+01:00

Will Koehrsen - @koehrsen_will:

Develop new algorithms as a PhD student: $30k/year

Use pre-built sklearn models as a data scientist: $120k/year

Build regression models in excel as a hedge fund analyst: $200k/year

Make pie charts as a CEO: $14 million/year

quote from Steve Jobs from an old interview:

Jobs: I actually lost $250,000,000 in one year when the stock went down. [laughs]

Playboy: You can laugh about it?

Jobs: I’m not going to let it ruin my life. Isn’t it kind of funny? You know, my main reaction to this money thing is that it’s humorous, all the attention to it, because it’s hardly the most insightful or valuable thing that’s happened to me in the past ten years. But it makes me feel old, sometimes, when I speak at a campus and I find that what students are most in awe of is the fact that I’m a millionaire.

Sean Carey - @Mac_Watershed:

Just hit ‘submit’ on my 5th NSERC Discovery Grant application. Reflecting on 25 years of research in Yukon. The hits, the misses and all that’s shaped me. The environment has changed, I have changed, but a few things remain the same: the pipe, and the wonder of it all.

presentations at AGU2018

2018-10-16T08:16:00+02:00

AGU 2018 in Washington, D.C. is shaping up to be a great conference! I know already quite a few people who will be attending – I am really looking forward to meet all these wonderful people! Secondly, our session did not get merged! I think we will be a small power poster session with wonderful presenters! And I will be involved in a few talks (see below). I’m really looking forward to meet you all in Washington!

Authors	Title	Date	Time	Location	Session
Claus Haslauer, Max Allmendinger, Sebastian Gnann, Theresia Heisserer, András Bárdossy	H21A-05: Interpolation of Regional Groundwater Quality Parameters With Categorical (Land Cover) and Real-Valued Secondary Information in the State of Baden-Württemberg, Germany	Tuesday, 11 December 2018	9:00-9:15	154 AB	H21A: Advances in Quantifying Impacts and Extents of Land Use/Land Cover Change on Hydrology II
Anke Wiener, Jürgen Braun, Norbert Klaas, Claus Haslauer	H23B-05: Planning of a Groundwater Remediation Using Nano Zero Valent Iron Particles	Tuesday, 11 December 2018	14:40-14:55	146 A	H23B: Innovations in Subsurface Contaminant Transport and Remediation III
Bo Xiao, Claus Haslauer, Geoffrey C Bohling, András Bárdossy	H23O-2599: Including Multiple Types of Information Measured at Non-Colocated Locations for Simulation of One Spatially Distributed Variable - Hydraulic Conductivity at the MADE Site	Tuesday, 11 December 2018	13:40-18:00	H23O-2599	H23O: Space–Time Data and Models Posters
Jeremy Bennett, Claus Haslauer, Philippe Renard, Olaf Cirpka	H12C-06: Data, or Geology… or Both? A Multi-Model Analysis of Solute Plume Behavior in a Synthetic Braided-River Deposit	Monday, 10 December 2018	11:35-11:50	146A	H12C: Advances, Breakthroughs, and Challenges in Hydrogeologic Sciences I

AGU2018 H114

2018-07-30T16:16:00+02:00

I would like to invite you to the following session at #AGU18:

title: “Space-Time Data and Models” — click here to submit an abstract
ID: H114
co-convener: Laureline Josset

The problem of estimating a variable at unobserved locations and/or times is important for many areas of research, including geosciences, civil-/ environmental engineering, soil sciences, agriculture, ecology, forestry, meteorology / climatology, oceanography, health / epidemiology.

The amount of data gathered is increasing (e.g., advances in measurement technologies, remote sensing, or citizen science). Challenges remain related to the interplay between heterogeneous measurements and improvements in models that can make use of the various types of data. This session aims to bring contributions together that demonstrate how to improve datasets and maximise their use through measurement techniques, statistics, and modelling, e.g., via

innovative ways to measure data in the environment;
the incorporation of innovatively measured data into modelling (usefulness, relevant scale);
the inclusion of as much information as available to improve prediction (secondary / heterogeneous data, data on different scales);
the consideration of the variability in the quality of the measurements;

Please find a pdf about the session here.

GeoEnv2018

2018-07-06T10:03:00+02:00

The wonderful conference “Geostatistics for Environmental Applications” (GeoENV) in Belfast ended a couple of weeks ago. Queen’s University hosted us and served as a spectacular location for the conference and the conference dinner. The nice atmosphere between the attendants has been an outstanding characteristic of this conference series that makes it worth for me to attend regularly! Certainly, I had outstanding scientific conversations during the conference. The final pints at the pub on the final evening demonstrated wonderfully how similar we are in our thoughts, perceptions, and understanding of scientific, societal, and political issues across our diverse backgrounds.

Our host: Queen’s University in Belfast

A common theme across many presentations were various approaches to use secondary data to improve the estimation of the variable of primary interest. Gregoire Mariethoz uses as much information as he can from remote sensing (e.g., various channels of remotely sensed images) to fill in gaps between raster images or in observed time-series of discharge. Jaime Gomez-Hernandez fuses precipitation measurements from radar images and rain-gauges. I use categorical (e.g. land-cover) information and other related real-valued measurements to better map groundwater quality parameters (the related paper was accepted during the conference). I also showed our approach to fuse different measurement types with different support and uncertainty. In discussions it became quite obvious that incorporating the varying quality of measurements into one model is one area of research that need our attention.

Peter Atkinson showed a related and simpler version of Peter Diggle’s triangle:

Peter Atkinson’s view of the world and of measurements.

HyVR

2018-06-08T09:03:00+02:00

Jeremy Bennett (@drifitngtides) published his Hydrogeological Virtual Realities simulation package.

the paper is published in Groundwater
the source code of HyVR is available on github
the documentation is online

Examples of spatially distributed fields of hydraulic conductivity simulated using HyVR.

You can find out more about Jeremy on his homepage. If you are interested in object-based simulations, troughs, or if you have any other inquiries – please contact us!

Stats of My Research Library

2018-03-05T09:03:00+01:00

The new version of Script Debugger made me play with AppleScript. Of course, I had to add some python.

I played with Script Debugger and my Research Library, Papers. While Papers doesn’t perform very well (anymore? I do have a fairly large library on an external USB3 hard drive), and is not the most stable software I use, its AppleScirpt Dictionary is wonderful. I am using continuously to get recent references that I collect in OmniFocus into Papers.

Now, here is what I did:

I tried in Script Debugger to get the publication year of each of the publications that I have in my database. That worked nicely. Debugging applescripts is a so much improved experience compared to the default AppleScript script editor. This is what the AppleScript does:
- loop over every entry in my papers database
- figure out what the publication year is
- append the year to a list
- at the end, missing values are ignored, via set myList to strings of pub_yrs
- the variable myList is returned to python in the call of the AppleScript.
I figured out, how to call an AppleScript from within python, using py-applescript (installed via pip install py-applescript and pip install PyObjC) and return a value (myList). The list is converted to a numpy array, and a normed histogram is plotted

The figure below shows a normed histogram of the publication dates in my Papers database:

‘Relative frequencies of publication years in my Papers library’

As you can see, not surprisingly, my reading (and knowledge) is biased towards recent research. However, I do have a few classics. My oldest reference is from 1870, and, of course, related to dependence ;-)

GROVE, W R. 1870. “Use of the Word ‘Correlation’.” Nature 1 (13): 335–35. doi:10.1038/001335b0.

Here is the full script:

Copula Based Geostatistical Code in Operational Use at LUBW

2018-01-09T12:06:00+01:00

After I had finished my PhD I started to work on an exciting project: improving the maps that help the state agency of the environment in Baden-Württemberg, Germany (LUBW) assess the state of the state-wide groundwater resources.

The European Water Framework Directive and related national law mandates that the water resources are monitored. The state of Baden-Württemberg maintains an extensive observation network for this and other purposes in which about 300 solutes are monitored at least annually. Maps are produced for each of those solutes and these maps form the basis for decisions related to water resource management, e.g., if a certain area should be monitored more closely.

Previous methodologies used to create these maps had various problems: Land-use categories used as secondary information imposed unrealistic sharp boundaries in the solute maps, Kriging based approaches led sometimes to unrealistic negative-valued estimates, stationary within the large domain (~40,000km²) was an unrealistic assumption, among others.

Hence, we developed the concept of locally mixed distributions that are based on the composition of the land cover within the neighbourhood of each interpolation location. The local distribution varies at each interpolation location and is then used as secondary information for spatial interpolation. Categorical secondary information such as land cover can be included in a quantitative model of spatial dependence for interpolation purposes.

I’d like to thank my colleagues Theresia Heißerer, Michael Eisele, and András Bárdossy who have been instrumental in advancing the geostatistical methodology and bringing the software into operational use.

At the same time, I’d also like to thank my colleagues at the state agency of the environment, Burkhard Schneider, Wolfgang Feuerstein, and Emil Hildenbrand for their wonderful cooperation, their recognition of the problem, and their eagerness to solve this real-world problem with innovative geostatistical methods!

Profiling Scientific Python Code

2017-12-06T17:06:00+01:00

This post explains my current profiling strategy (mostly for my own reference). It has proven useful to first make the code work what you want to do. Based on this working version, it is possible to identify bottlenecks. Then, a two-tier strategy has been proven useful:

Profiling at the macro level: Which function is the bottleneck?
Profiling at the micro level: Which line in the function identified in the first step is the bottleneck?

Macro

Brett Slatkin gives a good overview in his book “Effective Python” (amazon link)

“Python provides a built-in profiler for determining which parts of a program are responsible for its execution time. This lets you focus your optimization efforts on the biggest sources of trouble and ignore parts of the program that don’t impact speed. […] Python provides two built-in profilers, one that is pure Python (profile) and another that is a C-extension module (cProfile). The cProfile built-in module is better because of its minimal impact on the performance of your program while it’s being profiled.”

cProfile can be called like this

python -m cProfile <myscript.py>

You can also sort the output by cumulative time spent per function

python -m cProfile -s cumulative <myscript.py>

The output can be also saved to an ASCII file, here <cProfile_output.prof>

python -m cProfile -o <cProfile_output.prof> <myscript.py>

Visualizing Profile-Results

Snakeviz

Snakeviz can read output generated from cProfile

snakeviz <cProfile_output.prof>

and creates a “sunburst”

gprof2dot

gprof2dot can read output generated from cProfile

gprof2dot.py -f pstats <cProfile_output.prof> | dot -Tpng -o output.png

and generates a dot graph

Micro

line_profiler

line_profiler is a module for doing line-by-line profiling of functions.

in your script, you decorate the functions you want to profile with @profile.
```
@profile
def slow_function(a, b, c):
    ...
```
call the kernprof script
```
kernprof -l <myscript.py>
```

view the results

python -m line_profiler myscript.py.lprof

`timeit`

The timeit module can be used to measure the performance of small code snippets (e.g., when you identified the worst performing line via line_profiler, and you are testing out alternatives).

`cProfile` as decorator

…

this is another useful overview
one could use pystone to make performance results comparable between different hardware (e.g., between different iOS hardware)

Come Talk to me at AGU Fall Meeting 2017

2017-10-11T17:06:00+02:00

I will be at the AGU Fall Meeting (website, scientific program), New Orléans, 11-15 December, 2017. I’m looking forward to the new location and I am delighted to be among such refreshing speakers. Please find details of the presentations I am involved in below. I’m looking forward to talk to you!

Authors	Title	Date	Time	Location	Session
Jeremy Bennet, Martin Ross, Claus Haslauer, Olaf Cirpka	H34C-02: An open, object-based modeling approach for simulating subsurface heterogeneity	Wednesday, 13 December 2017	16:15-16:30	288-290	H34C: Groundwater Flow and Transport in Heterogeneous Media: New Insights from Experimental, Numerical, and Stochastic Investigations II
Bo Xiao, Claus Haslauer, Geoffrey Bohling, András Bárdossy	H34C-03: Comparison of Multivariate Spatial Dependence Structures of DPIL and Flowmeter Hydraulic Conductivity Data Sets at the MADE Site	Wednesday, 13 December 2017	16:30-16:45	288-290	H34C: Groundwater Flow and Transport in Heterogeneous Media: New Insights from Experimental, Numerical, and Stochastic Investigations II
Claus Haslauer, Max Allmendinger, Sebastian Gnann, Theresia Heisserer, András Bárdossy	H53O-07: Interpolation of Regional Groundwater Quality Parameters With Categorical and Real-Valued Secondary Information in the State of Baden-Württemberg, Germany	Friday, 15 December 2017	15:10-15:25	293-294	H53O: Regional Groundwater Quality, Availability, and Sustainability: Advances, Methods, and Approaches for a Complex, Changing World I
Claus Haslauer, András Bárdossy	H21H-1577: Multivariate Non-Symmetric Stochastic Models for Spatial Dependence Models (Invited)	Tuesday, 12 December 2017	8:00-12:20	Poster Hall D-F	H21H: Prediction of Hydrologic Behavior from Sparse Information Using Statistical and Machine Learning Techniques I Posters

The following table lists talks from my collaborators – you might find those interesting as well!

Authors	Title	Date	Time	Location	Session
Julia Knapp, Karsten Osenbrück, Matthias Brennwald, Olaf Cirpka	H13P-01: Using high resolution measurements of gas tracers to determine metabolic rates in streams	Monday, 11 December 2017	13:40-13:55	298-299	H13P Groundwater-Surface Water Interactions: Identifying and Integrating Physical, Biological, and Chemical Patterns and Processes Across Scales III
Olaf Cirpka, Matthias Loschko, Thomas Wöhling, David Rudolph	H52E-07: Accounting for the Decreasing Denitrification Potential of Aquifers in Travel-Time Based Reactive-Transport Models of Nitrate	Friday, 15 December 2017	11:50-12:05	293-294	H52E Nonpoint Source Pollution in Groundwater, Vadose Zone, and Surface Waters: Assessments, Mechanisms, and Control Strategies I
Ning Wang, András Bárdossy	H23C-1664: Investigation of the Impact of Precipitation Uncertainty on Spatially Distributed Hydrological Modelling	Tuesday, 12 December 2017	13:40-18:00	Poster Hall D-F	H23C Diagnostics, Sensitivity, and Uncertainty Analysis of Earth and Environmental Models III Posters

Spatial Statistics Conference 2017 Lancaster

2017-07-04T17:06:00+02:00

We will be at the Spatial Statistics Conference in Lancaster, UK, July 5-7

I will give a presentation entitled “Spatial Estimation: Dependence, Copulas, and Secondary Information – Using Groundwater Quality Parameters in Baden-Württemberg” with my co-authors S. Gnann, T. Heißerer, and A. Bárdossy on Tuesday July 5th at 11am in the Frankland Auditorium.

Note: see my posts about the conference here and here.

Censored Measurements and Portion of True Zeros in Geo-hydrology

2017-06-29T13:57:00+02:00

I published a new paper with my coauthors Jessica Meyer, András Bárdossy, and Beth Parker entitled “Estimating a Representative Value and Proportion of True Zeros for Censored Analytical Data with Applications to Contaminated Site Assessment” in Environmental Science & Technology (with Suplemental Information).

What's the difference between “zero” & “non-detect” for #contaminants? A new method to estimate # of true zeros: https://t.co/CZOhDTbzvg pic.twitter.com/J9R0YLMUQH
— Env Sci & Tech (@EnvSciTech) June 28, 2017

With Jessi I had had the idea that this might work quite some time ago, but it took some time to get the analysis done and to get it in a concise form. I am pretty happy with the outcome. The statistical model is parsimoneous and leads to nice results at a real field site.

The following figure shows that the likelihood function has a better optimum when the proportion of true zeros is estimated in addition to the typical parameters of a distribution function (up to a fairly large portion of censored values):

To my knowledge this is one of only few studies based on real data that incorporate censored measurements in a meaningful way. In our application we estimated the mass of a solute at certain locations in a given geological section. Hence this result has important implications for remedial design. Even more, we think this has direct implications for any variable that is measured in nature.

Due to the strict space-limitations for an ES&T paper, there are some really nice figures left out in the paper, which are plotted in the suplemental information, e.g.,

regarding a verification of the frequency of true zeros in the case of a precipitation data-set;
an analysis of the proportion of true zeros of a regional groundwater quality data-set (contaminants with a relatively short time in the environment exhibit fairly large portions of true zeros);
information regarding the robustness, stability, and unbiasedness of the method;

Micro and Macro Structures

2017-06-27T09:36:00+02:00

I published a new paper with my coauthors András Bárdossy and Ed Sudicky entitled “Detecting and Modelling Structures on the Micro and the Macro Scales: Assessing Their Effects on Solute Transport Behaviour” in Advances of Water Resources.

1/6 new paper: #geostatistics #solute_transport #stationarity #boundary_layer #Copula micro- and macrostructure https://t.co/xKcqM5bII8
— Claus (@planetwater) June 27, 2017

2/6 does given spatial data constitute one stationary domain, or is there boundary layer (“macro structure”) separating stationary domains?
— Claus (@planetwater) June 27, 2017

3/6 paper contains algorithm to detect and locate that interface or boundary layer and successfully matches previously outlined interfaces
— Claus (@planetwater) June 27, 2017

4/6 within each macrostructure, the microstructure was modelled with both Gaussian and non-Gaussian models, all estimated given the data
— Claus (@planetwater) June 27, 2017

5/6 evaluates effects of the four scenarios with/no macrostructure and Gaussian/non-Gaussian microstructure on solute transport behaviour
— Claus (@planetwater) June 27, 2017

6/6 depending on what is important (e.g., time of exceedance of some threshold or peak concentration), you need to focus on what to model.
— Claus (@planetwater) June 27, 2017

Own Your Writing

2017-06-21T09:36:00+02:00

On multiple occasions, I have experienced recently how important it is for me to own what I write. For me, this means that I publish my own website and my own blog (this one). This comes at some cost: I own the domain, I pay for the hosting, there is no advertisement. There is also some non-monetary cost: I keep up with the underlying techniques of static site generators, word-press installations, plugins, etc. I do enjoy it, but the point is, other possibilities exist where the setup is simpler and the cost is less. However in those cases, you don’t own what you write.

Coincidently, parallel to the events that I hinted at above and about which I might write in the future, there appeared two relevant related posts on Daring Fireball recently: “Fuck Facebook” and “On Giving a Shit”. In these posts, Facebook is used as an example for a closed solution for which users do not pay with money. In those posts, John Gruber

advises not to link to anything on Facebook (difficult or impossible to read if not a member; possibility of Facebook locking non-members out in future is possible);
points out that Facebook posts are not indexed in search engines and are not archived in the Internet Archive;

In another funny twist of fate, I had the old episode 90 of The Talk Show from 2012 lined up on my podcast player, where John Gruber and Dan Benjamin talk about these same and other Facebook issues (starting at about 1:10:50):

What sense does it make to require credentials from Facebook to login to Spotify?
Are “we” old farts who do the equivalent of using fax machines when we insist on email when everybody is on Facebook messenger?
Where does this end up? Will we need a Facebook credentials to get a bank account or an organ?

My thoughts:

More and more often I encounter pages online, where the content is hidden to me. I do think this is not what the internet is meant for.
You own what you write. In the largest sense possible of the word “own”. In German traditional publishing law, there is the VISdP who is responsible for the publication. I think if you are the responsible person, then you are responsible for what you write, with all its possible positive and negative effects. If you do this on your own site, you think about this likely more, before and while writing, so you end up with better quality of your text. This applies not only to Facebook but to other sites that do the hosting for you (e.g., Twitter, Instagram). This is the same reason I support initiative such as micro.blog. There have been other alternatives before, such as identi.ca or app.net). Also, there exist others today, like mathstodon. Somehow, a critical mass is required for these things, and it takes a while for those services to reach this point. Twitter certainly has this critical mass now, but it also started with zero users.
Is this really a valid argument, that “the old farts” rely on outdated technology? Or would rather everybody post to their own site, if it was less costly, both technically and monetarily? For my webpage and my blog I have both an installation of pelican running where python, css, and some knowledge about how a static blogging engine works are required, and this blog is running on my own hosted domain in a combination of wordpress / phpMyAdmin SQL. This is certainly more involved than posting on Twitter.
Playing is fundamentally important, hence the release of the new JSON feed - format is awesome! Thank’s to Manton Reece’s WordPress plugin, planetwater.org has now also a JSON feed (in addition to RSS and Atom), and yay, is it nice to read! Check out the New Yorker’s JSON feed or the New York Times’ JSON feed (via scripting news). This is the reason why I whipped up this pythonic JSON “feed reader”:

It’s going to be interesting if and how quickly JSON feeds are going to be supported. The outlook is not bad, for example, Reeder for iOS recently introduced JSON support. There are open source feed readers (on macOS at least vienna and most recently in pre-beta evergreen).
Particularly, in the university environment where I work, I want to treat students as equal as possible. This means, I do not want to enforce a membership anywhere — how do other academics and students see this?

Encrypting Email

2017-03-16T17:06:00+01:00

Secure email has been around for a while, for example, gpg tools have been around for macOS since quite some time. A recent podcast episode of the Mac Power User podcast tipped me to look at certificates, the relatively easy setup process within apple mail. It was only a quick search from there that I discovered that my employer, the University of Tübingen provides such certificates, issues such certificates.

The University of Tübingen provides secure email using S/MIME based certificates within the framework of the “public key infrastructure” of the german research net (DFN)

Die Universität Tübingen unterstützt das S/MIME-Verfahren im Rahmen der Public-Key-Infrastruktur (PKI) des Deutschen Forschungsnetzs (DFN).

The most effort requires to walk by the user help desk, which is actually a wonderful distraction given the current spring weather!

Update Friday; March 17, 2017: Nice overview comparing S/MIME and OpenPGP:

on macOS at the mac observer
on iOS also at the mac observer

HGS user meeting 2017 Bayreuth

2017-02-28T17:06:00+01:00

We will be at the HydroGeoSphere User Conference in Bayreuth!

HydroGeoSphere Syntax and hgspy

HydroGeoSphere grammar & syntax highlighting! If you want to have more control over your grok file, please feel free to check out the HGS syntax highlighter on github!
Emilio Sanchez and I put together a collection of python scripts to facilitate the generation of grok files, running HydroGeoSphere. We call it hgspy. We’re planning to extend it to some basic post-processing. It lives in a git repository on bitbucket: hgspy.

If you are interested, please do not hesitate to contact us!

Update 20170317: the hgs grammar got featured on the aquanty blog!

Presentations

Shanghua and Bo will give the following presentations:

Modelling of Vegetation Dynamics including Feedbacks to Hydrology

Shanghua will present her work in H36 NWIII on Monday at 3pm

Spatial Dependence of the MADE- Hydraulic Conductivity Data-Set

Bo will present his work in H36 NWIII on Tuesday at 11am

AGU 2016

2016-12-07T11:11:00+01:00

I will be at the “AGU fall meeting” taking place in San Francisco, USA from Monday (December 12th) to Friday (December 16th). Please contact me, if you want to chat with me in person. And please check out and come and talk to me at the presentation I will be giving on Monday and on Thursday

Looking forward to meet you there!

Asymmetry in Spatial Dependence Structures

The poster was upgraded to a presentation, which will take place on Monday morning:

Monday, 12 December 2016 09:15 - 09:30 Moscone South - 302

In this poster I can show you how non-Gaussian dependence (non symmetric dependence) can be quantified, is encountered frequently in data, can be modelled (simulations of spatially distributed random variables), and what impacts such an improved description has on dependent parameters (such as solute transport behaviour based on high-dimensional hydraulic conductivity fields.

Link to the AGU calendar.

Details of Claus’ poster presentation
date	Monday, 12 December 2016
time	13:40-18:00
location	Moscone South - Poster Hall
number	NG13A-1699
title of talk	“Asymmetry in Spatial Dependence Structures”
Authors	Claus P. Haslauer, András Bárdossy

Predict Breakthrough Curves based on Structural Parameters of Heterogeneous K Fields

It is desirable to predict the shape of breakthrough curves downgradient of a solute source from subsurface structural parameters (as in the small-perturbation macrodispersion theory) both for realistically heterogeneous fields, and at early time, before any sort of Fickian model is applicable. Using a combination of a priori knowledge, large-scale Monte Carlo simulation, and regression techniques, we have developed closed-form predictive expressions for pre- and post-Fickian flux-weighted solute breakthrough curves as a function of distance from the source (in integral scales) and variance of the log hydraulic conductivity field. Using the ensemble of Monte Carlo realizations, we have simultaneously computed error envelopes for the estimated flux-weighted breakthrough, and for the divergence of point breakthrough curves from the flux-weighted average, as functions of the predictive parameters. We have also obtained implied late-time macrodispersion coefficients for highly heterogeneous environments from the breakthrough statistics. This analysis is relevant for the modelling of reactive as well as conservative transport, since for many kinetic sorption and decay reactions, Laplace-domain modification of the breakthrough curve for conservative solute produces the correct curve for the reactive system.

Link to the AGU calendar.

Details of Scott’s presentation
date	Thursday, 15 December 2016
time	14:25-14:40
location	Moscone West - 3014
number	H43N-04
title of talk	“Prediction of Breakthrough Curves for Conservative and Reactive Transport from the Structural Parameters of Highly Heterogeneous Media”
Authors	Scott K. Hansen, Claus P. Haslauer, Olaf A. Cirpka, Velimir V. Vesselinov

Geostatistics 2016

2016-09-03T11:01:00+02:00

I will be at the “10th International Geostatistics Congress” taking place in Valencia, Spain from Monday (September 5th) to Friday (September 9th). Please contact me, if you want to chat with me in person. And please check out and come and talk to me at the presentation I will be giving on Monday.

See the detailed program online.

Looking forward to see you there!

Interpolation, Secondary Information, Land Use, Nitrate

Details of Claus’ presentation
date	Monday, 05 September 2016
time	15:20
location	parallel session S7, yellow cube
title of talk	“Spatial Estimation: Dependence, Copulas, and Secondary Information – Using Groundwater Quality Parameters in Baden- Württemberg”
Authors	S. Gnann, T. Heißerer, C. P. Haslauer, T. Heisserer, A. Bárdossy

FHDGGV 2016

2016-04-11T11:01:00+02:00

I will be at the “25. Tagung der Fachsektion Hydrogeologie in der DGGV 2016” in Karlsruhe this week. Please contact me, if you want to chat with me in person. And please check out and come and talk to me at the presentations I am involved in (see below).

See the detailed program online.

Looking forward to see you there!

Interpolation, Secondary Information, Land Use, Nitrate

Details of Claus’ presentation
date	Thursday, 14 April 2016
time	11:00 AM (O 9.4)
location	Plank Hörsaal, Geb. 40.32
title of talk	“Räumliche Interpolation von Grundwasserqualitätsparametern mit Hilfe von Copulas und Sekundärinformation”
Authors	C. P. Haslauer, T. Heisserer, A. Bárdossy, B. Schneider, E. Hildenbrand , W. Feuerstein

Geological Structure, Anisotropy, Solute Mixing

Details of Jeremy’s presentation
date	Wednesday, 13 April 2016
time	14:15 PM (O 15.8)
location	Plank Hörsaal, Geb. 40.32
title of talk	“The Impact Sedimentary Anisotropy on Solute Mixing in Groundwater”
Authors	J. P. Bennett, C. P. Haslauer, O. A. Cirpka

Nitrate, Agriculture, Arid, Climate Change, Irrigation, Climate Change

Details of Carolin’s presentation
date	Wednesday, 13 April 2016
time	13:30 PM
location	Plank Hörsaal, Geb. 40.32
title of talk	“Understanding Subsurface Pathways of Nitrate Transport at Catchment Scale - A Case Study in the Semi-Arid Mediterranean Lerma Catchment”
Authors	C. Thesenvitz, C. P. Haslauer, O. A. Cirpka, D. L. Rudolph

Aquifer Characterization, Hydraulic Tomography, Tracer Test

Details of Emilio’s presentation
date	Friday, 15 April 2016
time	15:15 PM
location	P 13.1
title of talk	“Improved aquifer characterization using a combination of Hydraulic Tomography and Tracer Testing”
Authors	E. E. Sanchez-León, C. Leven, C. P. Haslauer, O. A. Cirpka

AGU 2015

2015-12-07T11:01:00+01:00

I will be at the American Geophysical Union Fall Meeting in San Francisco next week (Dec 14-18). Please contact me, if you want to chat with me in person. And please check out and come and talk to me at the presentations I am involved in (see below).

Also note that there’s a Hydrologists Bingo happening! ;-)

Spatial Dependence, I built a Sandbox

Details of my poster on Thursday
date	Thursday, 17 December 2015
time	13:40 PM - 18:00 PM
location	Moscone South, Lower Level
title of talk	“Parameterization, Spatial Simulation, and Quantified Effects of Non-linear Spatial Dependence”
Authors	Claus P. Haslauer, András Bárdossy
ID	H43D-1534

Impacts of Climate Change on the Hydrology in Semi-Arid Catchment in Spain

I will be presenting work of Diane von Gunten’s dissertation, who is to be defended in January. She performed detailed numerical simulations of the hydrology in a small semi-arid catchment in Spain. The presentation consists of three key components:

The calibration of a transient integrated water flow model (surface water – ground water – evapotranspiration) of the catchment that recently underwent the well monitored transition from dry land to irrigation farming. The process of calibration involved numerical grid-coarsening.
She evaluated the effects of changed forcings (different meteorological time-series, climate change, GCM, RCM, weather generator) on the coupled hydrosystem components.
She evaluated the usefulness of meteorological drought indices for the assessment of hydrological measures (discharge, hydraulic conditions in the aquifer)

Details of my poster on Friday
date	Friday, December 18th, 2015
time	8 AM - 12:20 PM
location	Moscone South, Lower Level
title of talk	“Integrated Modelling of Climate Change Impacts in an Irrigated, Semi-arid Catchment”
ID	H51I-1503
Authors	Diane von Gunthen, Claus P. Haslauer, Thomas Wöhling, David Rudolph, Olaf Cirpka

Occurence of Helical Flow in Cross-Bedded Sediments and Consequences for Transverse Mixing

Details the talk on Friday
date	Friday, December 18th, 2015
time	14:10 PM - 14:25 PM
location	Moscone West - 3016
title of talk	“Occurence of Helical Flow in Cross-Bedded Sediments and Consequences for Transverse Mixing”
ID	H53K-03
Authors	Olaf Cirpka, Yu Ye, Jeremy Bennett, Gabriele Chiogna, Massimo Rolle, Claus Haslauer, Alberto Bellin

Looking forward to see you there!

Talk in Tübingen: GeoEnv Seminar

2015-10-26T10:30:00+01:00

I will be presenting this coming Friday (Oct-30) work related to interpolating groundwater quality parameters with

non-Gaussian dependence
secondary information via locally mixed distributions in a certain neighbourhood of an interpolation location
including censored measurements (e.g. measurements below detection limit)

The talk will be within the frame of the “GeoEnviron” seminar series:

Details of my talk on friday
date	Friday, October 30, 2015
time	03:15 PM - 04:15 PM
location	Lecture Hall (Room 320) of the Department of Geoscience, University of Tübingen, Hölderlinstr. 12, 1st floor
title of talk	“Maps and Uncertainty for Regional Groundwater Quality Including Categorical Secondary Information and Below Detects”

Looking forward to see you there!

Job Announcement

2015-10-01T12:30:00+02:00

I have a position to be filled. See pdf here or announcement below:

announcement: October 1st, 2015
starting date: October 14th or when suitable candidate is found
funding: 0.75 TVL E-13 for 3 years
location: Tübingen, Germany

Job Description

The successful candidate will be appointed to work as a doctoral researcher in the new Stochastic Hydrogeology Group of Claus Haslauer (funded by the German Research Foundation) within the Department of Hydrogeology at the University of Tübingen on the research project entitled “Realistic Spatial Dependence Structures of Aquifer Parameters: Modelling and Impact assessment”. The candidate will be associated with the International Research Training Group “Integrated Hydrosystem Modelling” and collaborate with the Kansas Geological Survey. The candidate’s research will focus on the development of multivariate copula based models for spatial dependence of aquifer parameters and on the analysis and impact assessment of the spatial dependence structure on dependent parameters, such as solute transport behaviour.

Candidate’s Profile

a Master’s degree (or equivalent) in mathematics/physics, environmental engineering, quantitative geosciences, civil engineering, or computer sciences with a strong quantitative / mathematical background;
strong interest in multivariate statistics and application to real world data;
preferably good scientific programming skills, a good command of the English language (written and spoken);
commitment to conduct a PhD thesis involving development of novel multivariate models (copulae) and and detailed hydrogeologic numeric simulations.

Application Documents

please answer the question: “Why do you want to do this research?”;
your CV;
copy of university degree certificates, list relevant courses attended, transcript of marks awarded at Master level;
electronic version of research output (e.g. MSc thesis, research report, scientific publications)
name and contact details of up to three people as possible references.

Please submit your application as one pdf file of maximal 5MB per email to Claus Haslauer or contact him directly for any further questions. Severely disabled persons are employed preferentially given equal eligibility. Female candidates are encouraged to apply, explicitly.

Plans for the Fall

2015-09-16T14:54:00+02:00

As I am setting up this website of mine, fall is in the air. This is shaping up to be a busy fall. I will be

teaching a full course, “Environmental Modelling 1”. More on that later, hopefully with some blogging;
attending two conferences, the “Chapman MADE” conference, where I will be presenting work together with Geoff Bohling, and I will likely also head to San Francisco for AGU;
get back into learning Spanish. There’s a reason for that, and I will hopefully post more on this also in the fall;

I decided to set this webpage up with the following mindframe:

Pelican is based on python; really helpful has been this post
in that regard, the only alternative was Nikola
for now, I settled with the “SVBHACK” theme
so far, everything works well; things to do include:
- python syntax highlighting, likely using the render math plugin
- include ipython notebooks, likely via liquid_tags

Hello World!

2015-09-09T10:20:00+02:00

This is the content of my super blog post.

Claus Haslauer's Website

Nanopixel Programming

To Dos

New Things

The Köln Concert

EGU26 Geostatistics Session

resurrection

archival digg

low order moments

presentations at AGU2019

Still in the Yukon

presentations at AGU2018

AGU2018 H114

GeoEnv2018

HyVR

Stats of My Research Library

Copula Based Geostatistical Code in Operational Use at LUBW

Profiling Scientific Python Code

Macro

Visualizing Profile-Results

Snakeviz

gprof2dot

Micro

line_profiler

timeit

cProfile as decorator

More

Come Talk to me at AGU Fall Meeting 2017

Spatial Statistics Conference 2017 Lancaster

Censored Measurements and Portion of True Zeros in Geo-hydrology

Micro and Macro Structures

Own Your Writing

Encrypting Email

HGS user meeting 2017 Bayreuth

HydroGeoSphere Syntax and hgspy

Presentations

Modelling of Vegetation Dynamics including Feedbacks to Hydrology

Spatial Dependence of the MADE- Hydraulic Conductivity Data-Set

AGU 2016

Asymmetry in Spatial Dependence Structures

Predict Breakthrough Curves based on Structural Parameters of Heterogeneous K Fields

Geostatistics 2016

Interpolation, Secondary Information, Land Use, Nitrate

FHDGGV 2016

Interpolation, Secondary Information, Land Use, Nitrate

Geological Structure, Anisotropy, Solute Mixing

Nitrate, Agriculture, Arid, Climate Change, Irrigation, Climate Change

Aquifer Characterization, Hydraulic Tomography, Tracer Test

AGU 2015

Spatial Dependence, I built a Sandbox

Impacts of Climate Change on the Hydrology in Semi-Arid Catchment in Spain

Occurence of Helical Flow in Cross-Bedded Sediments and Consequences for Transverse Mixing

Talk in Tübingen: GeoEnv Seminar

Job Announcement

Job Description

Candidate’s Profile

Application Documents

Plans for the Fall

Hello World!

`timeit`

`cProfile` as decorator