Sometimes you have to show positive, zero and negative number in log scale. However you cannot take log of negative numbers and zero. But one could approximate it with a log transform modulus as stated here.

In Python with numpy:

from numpy import sign, abs, log10  
import matplotlib.pyplot as …

I keep needing a python code to generate the dielectric functions of plasmonic materials such as Au, Ag, Pd, and Pt. So I wrote a python version of LD.m.

LD.m is a matlab file written by Bora Ung …

Amazon provides high performance computing capabilities through their EC2 service. You can find more information here

They provide a 750 hr free instance with their a free-tier program. If you want more resources, you can pay for it. See the pricing, pricing seem very reasonable.

I wanted to see …

Here is how I was implementing plasmonic materials in meep 1.1. Unlike Meep 1.1, Meep >= 1. 2 changed the way materials are defined.

Here I will describe how to change the material definition code from meep1.1 to meep 1.2 . Please note that one can still use …

My current apartment does not have a doorbell (Its strange but it is true). I went ahead and built a doorbell using two arduino pro-minis and two NRF24L01 transceivers. The melody to be played when a guest presses a button can also be controlled. I have four melodies programmed in …

For my doorbell project, I needed some melodies to be played on arduino. One can takes notes of a melody and write a corresponding arduino code.

I like airtel tune and wanted to play it with arduino. I got the notes from https://www.youtube.com/watch?v=3m5j5UIRqQc

Here …

DC power supplies are very handy for electronic projects. They help to apply bias/voltage to a device. Controlling it by a computer by a program is helpful in advanced projects where timing and accurate control is an issue.

I got my hands on a RIGOL DP832 which is three …

I have been interested in monitoring and keep track of my weight. In the past, I have used different phone apps to track my weight. They work reasonably well, but I was thinking of reading weight data directly from my weighing scale and upload the data to an online database …

Optical power meters in-conjunction with a detector are used to measure power from a laser source or monochromatic output.

At work, we use Newport 1918 power meter. This power meter comes with its own software. However, I was interested in controlling this instrument with python.

I wrote a python module …

Monochromator is used in optics research where a narrow bandwidth of light is required to be illuminated on a sample. I work with Princeton Instruments Acton SP2150i and needed a python program to control it.

I found the manual here and on page 9-10, I saw the serial commands for …