Reading meteorological parameters through a weather station connected to the Internet has gained great popularity. Here’s an example of how to set up a weather station, connect it to ThingSpeak and display the time series. We use the inexpensive and very popular Smart Weather Station from Netatmo in this experiment. Continue reading “ThingSpeak IoT Weather Station”
Computing the evolutionary spectrum of a short piano piece helps to recognize that music is the result of a complex interplay of temporal and spectral changes of sound. The MATLAB Audio Toolbox has numerous useful functions for spectrally analyzing music. Continue reading “Analyzing Music in the Time and Frequency Domain using MATLAB”
Color is an uncertain characteristic for the determination of minerals. Many minerals occur in a variety of different colors. Examples are quartz with its color variants amethyst, rose quartz or smoky quartz or feldspar with color variants like amazonite. However, if the minerals in a rock are reliably determined, their different coloring can be used to quantify them. In this example we use a simple RGB photo taken with a smartphone to determine the amounts of quartz, plagioclase, alkali feldspar and dark minerals such as biotite and hornblende in granite. To facilitate the differentiation of minerals, we use a principal component analysis (PCA), which is also used to unmix and classify spectral images such as satellite images (Trauth, 2020).