Peter Yu

I am a research and development professional with expertise in image processing, remote sensing and computer vision. With an educational background in systems design engineering and considerable research and development experience in industries ranging from district energy systems to medical imaging to cinematic visual effects, I am always looking for interesting problems to solve with significant real-world applications. This is my personal website where you can learn about my research and read some helpful tutorials and posts I have written. → More about me

Email: [user]@[host] where [user]=web and [host]

New and Updated Pages

Vintage style isochrone travel time map with Python, PyTorch and QGIS

A few years ago, an old isochrone map from 1914 made the rounds on Reddit. It showed the amount of time it would take to get anywhere in the world, starting from London, UK using the transportation methods available back in the day. Soon enough, someone made a new version that showed modern travel times. It's a beautiful map that I wanted as a poster, but the print was not available and it only showed the travel times from London. I decided to make my own version with a Python script and QGIS so I can generate the map from any starting point. Even without detailed travel route data, it turned out pretty well.

Isochronic travel times from Toronto, Canada

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2020/12/20 14:41 · Peter Yu

Add an Open Anaconda Prompt context menu item to folders in Windows

Ever wanted to open an Anaconda Prompt by right clicking the folder in Explorer in Windows 10? Git Bash has an entry in the right-click context menu and so does Powershell (just Shift + Right-Click). Anaconda doesn't have one by default and I wanted to add it. But none of the answers on Stack Overflow or a bunch of other sites worked. I finally got it working after reading the Wikipedia entry for cmd.exe.

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2020/07/02 16:18 · Peter Yu

Plot sunrise and sunset times in MATLAB or Octave

This tutorial shows you how to make a graph that plots the sunrise and sunset times in MATLAB or Octave. You'll learn how to shade the area above, below and between curves, use date and time formatted axis tick labels and draw grid lines for each tick mark in a custom colour. The result will look like this:

Sunrise and sunset graph generated by Octave

This code works in Octave but it should be compatible with MATLAB, which I don't have access to at the moment.

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2020/05/06 13:57

LaTeX script styles for math

When I was writing a paper, I needed a lot of mathematical variables. I had already used up so many letters in both plain text and bold face that I needed more styles for English letters. So I looked for ways of using different types of script styles in LaTeX equations. I already knew about \mathcal, which is used for math calligraphy but it only supports upper case letters when I really needed lower case variables. It turns out that a lot of the script styles in math mode are upper case only. I eventually found several ways of using lower case script letters in LaTeX equations, as well as a few other math mode styles that seem useful. I have listed them in this short tutorial.

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2012/09/05 21:23 · Peter Yu

Using Grep

This page is where I consolidate all my notes on the grep tool, which is available on Linux and Unix, and also on Windows as part of Cygwin. I usually use it on Cygwin, so these notes apply to that version of grep.

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2012/04/02 22:08 · Peter Yu

LightWave surfaces with the node editor

The nodal surfaces in LightWave are pretty neat and allow for some complex surfaces to be made. Surfacing like this is still quite new to me so I am going to start documenting the node set up for some surfaces here on this page. There probably will not be too many surfaces here (not enough time for 3D!) but I will add to it from time to time.

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2012/01/21 14:15 · Peter Yu

About Peter Yu I am a research and development professional with expertise in the areas of image processing, remote sensing and computer vision. I received BASc and MASc degrees in Systems Design Engineering at the University of Waterloo. My working experience covers industries ranging from district energy to medical imaging to cinematic visual effects. I like to dabble in 3D artwork, I enjoy cycling recreationally and I am interested in sustainable technology. More about me...

Feel free to contact me with any questions about this site at [user]@[host] where [user]=web and [host]

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