How to Tackle Programming Problems (Google Code Jam 2017 Qualification Round, Problem A)

Jessica YungProgramming, Uncategorized

This is a walkthrough of how one might start thinking about Problem A (small input) of Google Code Jam’s 2017 Qualification Round (April 8-9). Google posts excellent solutions to their problems, so the focus here will be that of the idea generation process or how one might begin to tackle such problems. Full problem statements can be found here. Problem A (Oversized … Read More

What do the Kalman Filter Equations Mean? (Part 2: Update)

Jessica YungSelf-Driving Car ND

In my previous post, I explained the Kalman Filter prediction equations in a big-picture way. In this post I will explain the update equations. The equations to focus on are the last two. (We use the results from the first three equations in the last two equations.) Eqn 1: Updating the object state x: x’ is the predicted object state … Read More

What do the Kalman Filter Equations mean? (Part 1: Prediction)

Jessica YungSelf-Driving Car ND

In the second term of Udacity’s Self-Driving Car Engineer Nanodegree, you start out learning about Kalman Filters. You are given a bunch of equations. What do they mean? In this post I explain the prediction equations (left) in a big-picture way. I explain the update equations in my next post. Predicting the object state x: Equation: x is the object state. … Read More

Behavioural Cloning: Tips for Tackling Project 3

Jessica YungSelf-Driving Car ND

In this post I list tips that may be helpful for tackling Project 3 of Udacity’s Self-Driving Car Nanodegree, in which you train a neural network to drive a car in a simulator. The neural network learns from data of humans driving the car through the simulator, hence the project name ‘Behavioural Cloning’ – it’s trying to imitate the way … Read More

Bugger! 4.2: Semicircle lane lines

Jessica YungProgramming, Self-Driving Car ND

Recap from the previous post: we’re trying to trace lane lines from a video. We just dealt with our pipeline spitting out zebra stripes, but now we’ve got a semicircle trace to deal with (see feature image above). What to do? Step 1: Plot intermediate steps to locate the bug Recall that our model is supposed to: Un-distort the test image … Read More

Mapping Economics

Jessica YungEconomics, Education

Scroll down for sample diagrams. Motivation: How can I contribute with my meagre knowledge of Economics? When you spend over twenty hours a week studying, you cannot help but ask, ‘Am I going to use a significant proportion of this later on in life, especially if I don’t become an economist? (No.) If not, why am I spending time learning … Read More

Bugger! 4.1: Zebra Stripes for Lane Lines

Jessica YungProgramming, Self-Driving Car ND

In Project 4: Advanced Lane Lines of Udacity’s Self-Driving Car Nanodegree, we use computer vision techniques to trace out lane lines from a video taken from a camera mounted at the front of a car, like so: Result I’m supposed to get In this series, I share some bugs I came across and how I tackled them. The code can … Read More