MATLAB and Python Recipes for Earth Sciences
Martin H. Trauth, University of Potsdam, Germany
It can happen that an electromagnetic field disturbs the images of cameras on microscopes with a periodic noise. While the specialists are looking for the source of the interference, I quickly wrote a MATLAB script to filter the noisy image.
Continue reading “Removing Periodic Noise from Images with MATLAB”
Quantifying the composition of substances in geosciences, such as the mineral composition of a rock in thin sections, or the amount of charcoal in sieved sediment samples, is facilitated by the use of image processing methods. Thresholding provides a simple solution to segmenting objects within an image that have different coloration or grayscale values. As an example we use thresholding to separate the dark charcoal particles and count the pixels of these particles after segmentation. Continue reading “Quantifying Charcoal in Microscope Images Using MATLAB, Part 2”
Paleoclimate time series are often very noisy due to the combined effect of low sedimentation rates, intensive bioturbation and small sample sizes (5-20 foraminifers). Adaptive filters may help to increase the signal-to-noise ratio of such time series where conventional methods such as fixed filters cannot be applied if optimal filtering is to be achieved, because the signal-to-noise ratio is unknown and varies with time. Continue reading “Adaptive Filters in Paleoclimatology – the Python Version”
Detecting, measuring and classifying transitions in climate time series is one of the most important applications in modern time series analysis (Mudelsee, 2000; Trauth et al., 2018, 2021). Three methods are presented here: sigmoid fit, ramp fit and change point detection. Continue reading “Analyzing Climate Transitions with MATLAB”
Variants of a map of northeastern Africa appear in recent publications (e.g., Trauth et al., 2021a, b) using coastlines from the GSHHG data set and topography from the ETOPO1 data set. Here I show how it was made. Continue reading “Creating a Map with Coastlines and Topo Contours with MATLAB”
We wanted to display pulsating circles on a map and save the result in a video. Here is part one, the pulsating circles. The map will come in the next post.
Continue reading “Creating a Bubble Chart Animation with MATLAB”
The popular online course on data analysis in the geosciences will be taught bilingual for the first time, using the two leading programming languages and development environments MATLAB and Python in parallel on 18–22 September 2023. The course is based on the 5th edition of my books MATLAB Recipes for Earth Science (Springer 2021) and Python Recipes for Earth Sciences (Springer 2022).
Continue reading “56th Online Shortcourse on MATLAB & Python Recipes for Earth Sciences”
A while back I wrote a post about John Aitchison’s Log-Ratio Transformation, Part 1, in the time domain and today Part 2 in the frequency domain. Here’s Part 3 with a MATLAB demonstration of a nice Aitchison example presented in an extended abstract by Pawlowsky-Glahn and Egozcue (2013). Continue reading “MATLAB Example to Illustrate John Aitchison’s Log-Ratio Transformation, Part 3”