LEAST-SQUARES METHOD IN GEOSCIENCES
Least-squares method is a popular approach in geophysical inversion to estimate the parameters of a postulated Earth model from given observations. This meth...
Posts
GEOPHYSICS
TIME-FREQUENCY ANALYSIS IN MATLAB
A signal has one or more frequency components in it and can be viewed from two different standpoints: time-domain and frequency domain. In general, signals a...
HYPOTHESIS TEST FOR THE SIGNIFICANCE OF LINEAR TREND USING THE MONTE CARLO SIMULATIONS
We pose a null hypothesis and enquire that given that the null hypothesis is true, how likely is the observed pattern of results? This likelihood is known as...
HOW TO AVOID COMMON MISTAKES IN ANALYZING CORRELATIONS OF TWO TIME-SERIES
Most often data analyst consider correlation between two time-series as a causation effect. Two time-series are correlated that does not imply that one cause...
ESTIMATION OF THE DEGREES OF FREEDOM FOR TIME SERIES
Numerical tests to understand the degrees of freedom in time series
NUMERICAL TESTS FOR SEISMIC RESOLUTION
Seismic resolution and fidelity are the two important measures of the quality of the seismic record and the seismic images. Seismic resolution quantifies the...
LOCATING EARTHQUAKES USING GEIGER’S METHOD
Simple earthquake location problem and its solution using Geiger’s method
EXPLORATORY FACTOR ANALYSIS
Factor Analysis is an exploratory data analysis method used to search influential underlying factors or latent variables from a set of observed variables
TIME SERIES ANALYSIS IN GEOPHYSICS
Time-series analysis is essential in most fields of science, including geophysics, economics, etc. Most of the geophysical data comes in a time-series format...
GETTING STARTED WITH OBSPY: DOWNLOADING WAVEFORM DATA
Obspy is an open-source Python framework developed for the processing of seismological data. In this post, I will introduce how to use Obspy along with some ...
SIMPLE WAVE MODELING AND HILBERT TRANSFORM IN MATLAB
We demonstrate how to model a simple wave, obtain its frequencies, apply Hilbert transform, and perform edge detection
PLOTTING SEISMOGRAMS WITH INCREASING EPICENTRAL DISTANCE [PYTHON]
Short demostration of how to plot the distance vs seismic waveforms and mark the P and S arrival times using the IASP91 earth model. Codes are included.
AUTOMATICALLY PLOTTING RECORD SECTION FOR AN EARTHQUAKE IN THE GIVEN TIME RANGE [PYTHON]
Python code to automatically plot the record section for the highest magnitude earthquake in the given time range
NUMERICAL TESTS ON TRAVEL TIME TOMOGRAPHY [MATLAB]
Introduction to the concepts of tomography with equations and codes. Introduction to the concepts of overdetermined, underdetermined and mix-determined probl...
PLOTTING THE GEOSPATIAL DATA CLIPPED BY COASTLINES IN PYTHON
In geosciences, we most frequently have to make geospatial plots, but the available data is unevenly distributed and irregular. We like to show the data, in ...
NON-LINEAR CURVE FITTING TO A MODEL WITH MULTIPLE OBSERVATIONAL VARIABLES [MATLAB]
How to fit data to non-linear model
UTILITIES
WRITE ASCII DATA TO MSEED FILE USING OBSPY
In this post, I will read a ASCII file whose first few lines contains the header information and then the three-component data. I will read using the pandas ...
WORKING WITH OBSPY AND BASEMAP
This post is aimed to resolve the issues regarding the conflicts of using obspy and basemap libraries together.
GMT TUTORIAL FOR BEGINNERS
The Generic Mapping Tools is widely used across Earth and Planetary and other fields of studies to process data and generate high-quality illustrations. This...
WRITING NETCDF4 DATA USING PYTHON
NetCDF file format has been designed for storing multidimensional scientific data such as temperature, rainfall, humidity, etc. In this post, we will see how...
READING NETCDF4 DATA IN PYTHON [PYTHON]
In Earth Sciences, we often deal with multidimensional data structures such as climate data, GPS data. It ‘s hard to save such data in text files as it would...
PYGMT: HIGH-RESOLUTION TOPOGRAPHIC MAP IN PYTHON [PYTHON]
A simple tutorial on how to plot high resolution topographic map using GMT tools in Python
PLOTTING TRACK AND TRAJECTORY OF HURRICANES ON A TOPOGRAPHIC MAP [PYTHON]
Short demostration of how to plot the track or trajectory of a hurricane on a map. Codes are included.
TOPOGRAPHIC MAP CLIPPED BY COASTLINES [PYTHON]
This post demonstrate how to use Python to set up clip topographic map based on coastlines.
TOPOGRAPHIC MAP WITH SHADING [PYTHON]
Generating GMT style shaded relief map in Python
HOW TO PLOT TOPOGRAPHIC STATION MAP [PYTHON]
We read the station information from a file to plot the 1 arc-minute relief map
PLOTTING 1 ARC-MINUTE GLOBAL RELIEF MAP [PYTHON]
Plotting 1 arc-minute topographic map in python
GMT ADVANCED TUTORIAL II
Plotting publishable quality maps using generic mapping tools (GMT)
GMT ADVANCED TUTORIAL
Plotting publishable quality maps using generic mapping tools (GMT)
WHY WE SHOULD USE GENERATORS? [PYTHON]
Generators don’t hold the entire result in memory. It yields one result at a time.
TECHNIQUES
SPEED-UP YOUR CODES BY PARALLEL COMPUTING IN PYTHON
With the increasing amount of data, parallel computing is quickly becoming a necessity. Modern computers comes with more than one process and we most often o...
ADVANCED 2D PLOTS WITH MATPLOTLIB IN PYTHON
Codes for plotting advanced 2D plots using matplotlib library in Python. Includes simple 2D plot, error bars, bar graphs, histograms, multiple plots, etc
TIME SERIES ANALYSIS: FILTERING OR SMOOTHING DATA [PYTHON]
In this post, we will see how we can use Python to low pass filter the 10 year long daily fluctuations of GPS time series. We need to use the “Scipy” package...
VISUALIZING POWER SPECTRAL DENSITY USING OBSPY [PYTHON]
Short demonstration of the ppsd class defined in Obspy using 3 days of data for station PB-B075
MONTE CARLO SIMULATION TO TEST FOR THE CORRELATION BETWEEN TWO DATASET [MATLAB]
We test for the correlation coefficients or the covariance between two sets of random numbers selected from normal distribution using the Monte Carlo simulat...
USING GITHUB FOR TEAM COLLABORATION
Tutorial on how to use Git and GitHub for team collaboration on a project. Content includes installing, setting up, creating a repository, making commits, un...
INTRODUCTION TO PYTHON FOR BEGINNERS
In this tutorial post, I give a quick demo of how to install Python (using anaconda) and then getting started with writing simple scripts.
LIFEHACKS
SOME HANDY MAC TWEAKS [MACOS]
Some handy tweaks for mac like relocating default screenshot location, renaming batch files etc
INTRODUCTION TO AUTOMATING MAC [MACOS]
Mac can be easily automated by the help of several tools such as automator, quick actions, applescripts
IPHONE SHORTCUT TO QUICKLY LOG BODY TEMPERATURE [IOS]
Shortcut code for quickly logging temperature in Apple health app
MAC QUICK ACTION TO RATE THE SONGS IN APPLE MUSIC APP [MACOS]
Quick action for mac to easily love, dislike, rate songs in apple music app
STATISTICS
STATISTICAL ANALYSIS [MATLAB]
Visualize the statistics of the data using MATLAB: mean, median, std, interquartile range, skewness, kurtosis, t-statistic
HYPOTHESIS TEST [MATLAB]
Using Randomization to test the disprove the null hypothesis
ESTIMATION OF THE DEGREES OF FREEDOM OF TIME SERIES [PYTHON]
Two time series with predominant linear trends (very low DOF) can have a very high correlation coefficient, which can hardly be construed as an evidence for ...
WEBAPPS
BUILD A FLASK WEB APPLICATION: SEA LEVEL RISE MONITORING
This post gives a quick introcution of how to build a web application using Flask and deploy on Heroku server. Then, I share my codes for building advanced w...
INTERACTIVE DATA VISUALIZATION [PYTHON]
A basic to advanced guide to making interactive plots in Bokeh.
