Cross-correlation is an established and reliable tool to compute the degree to which the two seismic time-series are dependent on each other. Several studies have relied on the cross-correlation method to obtain the inference on the seismic data. For details on cross-correlation methods, we refer the reader to previous works [see references].

Photo by Burak K from Pexels

It is essential to understand and identify the complex and unknown relationships between two time-series for obtaining meaningful inference from our data. In this post, we will take the geophysical data for understanding purposes. …


Image by Peter Fischer from Pixabay

The optimization is defined by the Wikipedia as “ the selection of a best element (with regard to some criteria) from some set of available alternatives” {Source: Wikipedia}. It is the picking of the “best” option from several available alternatives of accomplishing the same task. The goal of our optimization model is to give us the best possible result.

Source: GIPHY

Global vs. Local Optimization

Consider a hypothetical multi-modal function:


iPad is not a computer but it has the potential to be. A computer is a computer, don’t make it an iPad.

You must have come across the ad about the iPad Pro: “What’s a computer?”. From those ads, I derived that Apple is trying to converge the iPad Pro towards a real computer. However, recent moves from Apple are showing that it is rather trying to converge a computer towards an iPad!

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Apple made the iPad fast, probably much faster than many Intel-based computers. It has a touch screen that Macs have never got (and probably will never get) and it often comes in handy in some quick and easy tasks. Recently, Apple introduced the M1 chip into the iPad…


We look into the basics of Fourier analysis and learn to apply it to the synthetic and real signals to remove noise

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Fourier analysis is based on the idea that any time series can be decomposed into a sum of integral of harmonic waves of different frequencies. Hence, theoretically, we can employ a number of harmonic waves to generate any signal.

In this post, we will use Fourier analysis to filter with the assumption that noise is overlapping the signals in the time domain but are not so overlapping in the frequency domain.

Import libraries, create a signal and add noise

We created our signal by summing two sine functions at different frequencies (50Hz and 120Hz). …


Transfer learning using the pre-trained deep learning networks from MATLAB can be easily implemented to achieve fast and impressive results

I obtained the image data from Unsplash. I downloaded 42 cat images, 46 dog images, and 35 horse images for the input into the pre-trained Alexnet model in MATLAB. For details about the Alexnet network in MATLAB, see its documentation.

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Alexnet

AlexNet is a convolutional neural network that is 8 layers deep. The MATLAB has a pre-trained version of the network trained on more than a million images from the ImageNet database. The pre-trained network can classify images into 1000 predefined object categories.

The training for the 1000 object categories on a million images has made the network learn rich feature…


A wavelet series represents a real or complex-valued function by a certain orthonormal series generated by a wavelet. We cannot easily explain wavelet transform with a basic understanding of the Fourier Transform.

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Fourier Transform

The Fourier Transform is a useful tool to transform a signal from its time domain to its frequency domain. The peaks in the frequency spectrum correspond to the most occurring frequencies in the signal. The Fourier Transform is reliable when the frequency spectrum is stationary (the frequencies present in the signal are not time-dependent). …


One of the favorite parts of working in geophysics is without a doubt creating amazing visualizations. Visualizations are the best tool to effectively convey our findings to the scientific community.

GMT or generic mapping tools have become synonymous with plotting maps in Earth, Ocean, and Planetary sciences. It can be used for processing data, generating publication-quality illustrations, automating workflows, and even making awesome animations. Another great thing about GMT is that it supports many map projections and transformations and includes supporting data such as coastlines, rivers, and political boundaries, and optionally country polygons.

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I have talked about GMT 5 and…


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Science is dependent on technology as much as technology is dependent on science. I love science, and I love technology. Both of them are complementing and impacting my research career. Before I talk about my favorites for the tech products, I want to tell you that I am a geophysical researcher with a strong inclination towards data science. What I have learned and achieved so far and where I am heading is largely because of my decisions about switching to some gadgets. …


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I love my iPhone 12 mini and would be sad if Apple decided to remove this model in the future. But at the same time, I am relieved that I already bought it and am secure for at least 2 to 3 years. The handling and performance of the iPhone 12 mini would give a satisfying feeling after coming from the ginormous iPhone 8 Plus for over three years.

Love of the iPhone Mini Form Factor

Every time I would see an iPod in the Apple store, I used to think that I wish Apple made a phone of the same form factor. I usually carry an…


Photo by David Clode on Unsplash

Since Python by itself is slow, it becomes important to know the nitty-gritty of different components of our code for efficiency. In this post, we will look into the most common ways we loop in Python using a simple summing example. We will also compute the memory profile to inspect which way is the most memory-efficient for analyzing huge datasets.

Utpal Kumar

Data | Python | MATLAB | Productivity

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