Posts on Jakob Johnson

MARC Conference, Hawai'i

Tue, 22 Apr 2025 09:00:00 -0600

Kailua Bay (Fujifilm X-S10, 18-55mm)

A few weeks ago, I had the opportunity to present my research at MARC XIII in Kailua-Kona, HI. It’s the premier conference for nuclear forensics and nuclear chemistry. Since my research applies machine learning to nuclear forensics, it was a perfect venue to show off my work - and get to visit Hawai’i for the first time.

Kamakanohu Beach and outrigger canoe (Fujifilm X-S10, 18-55mm)

Building a Personal Website with Github Pages

Tue, 01 Oct 2024 12:00:00 -0600

Intro

Much of this content will be based on the existing docs of Github Pages but with a bit more detailed steps.

We’ll be using Jekyll in this, there are a number of other static website generators (such as Hugo), but since Pages has built in support for Jekyll, that’s where I’d recommend starting.

Prerequisites

You’ll need

a GitHub account
Ruby installed
- I’d recommend using RVM so as to not mess with your computer’s installation of Ruby
[Optional] Your own domain name.
- Register one at a registrar like Namecheap. They’re pretty inexpensive, usually ~$10/year. They often also have deals on free or super cheap domains for students

Note about Windows machines - I’d suggest setting up and using WSL for this. It will simplify installing things greatly.

Zion

Sun, 12 Mar 2023 13:10:31 -0600

Snowy Timber Top Mountain, Kolob Canyon Overlook (Fujifilm X-S10, 18-55mm)

Since grade school I’ve gone to southern Utah over spring break. Usually it was hiking in Moab (before all the massive new hotels popped up). In recent years I’ve used it as a spring training camp of sorts, riding bikes in the St. George sun before the roads defrosted up north.

Pytorch Tutorial

Wed, 16 Nov 2022 11:22:47 -0700

Most of the content here is from the Official Pytorch tutorial. I made this to be more concise and to present to a class.

You can get the notebook here.

PyTorch Background

Data in PyTorch is stored in Tensors, which are almost identical to NumPy arrays.

Their key differences are

Auto gradient calculation (with torch.autograd)
Ability to move to a GPU (with Tensor.to(device))

import torch

data = [[1,2,3], [4,5,6], [7,8,9]]
data_tensor = torch.tensor(data)
print(data_tensor)

tensor([[1, 2, 3],
        [4, 5, 6],
        [7, 8, 9]])

ones_tensor = torch.ones(size=data_tensor.shape, dtype=int)
print(ones_tensor)

# these tensors behave almost exactly like numpy arrays
print(ones_tensor @ data_tensor)

tensor([[1, 1, 1],
        [1, 1, 1],
        [1, 1, 1]])
tensor([[12, 15, 18],
        [12, 15, 18],
        [12, 15, 18]])

Datasets & DataLoaders

Some datasets are available from Pytorch’s own libraries, such as MNIST or Fashion-MNIST

Python Management with Pyenv

Wed, 17 Aug 2022 00:00:00 +0000

Why use Pyenv?

Python virtual environments have been a useful way of managing python packages and package versions for quite a while. With vanilla Python, virtualenv is available, and for more complex cases Anaconda is a popular choice. Using these keeps your system installation of Python free of unnessecary clutter and packages as well as making it really easy to share dependencies with pip freeze.

But what if some of the packages you wanted to install aren’t avaliable for your system’s installation of Python? Or what if your system is stuck on an old version of Python and you want to use the brand new shiny Python 3.13? That’s where pyenv comes in. It’s a series of shell ‘shims’ that seamlessly swap to different installations of Python. It’s frequently updated which means new versions of Python get added regularly so you can always stay up to date. Even better, since it’s simply shell commands you can install it without root access on your work machines!

About this Website

Fri, 12 Aug 2022 00:00:00 +0000

Hello there! Welcome to my personal website and/or blog! This’ll be a place to post my random tutorials as well as some life blogging/travel photos. I like to take photos and this’ll be a fantastic place to post them!

San Antonio Photos

Here’s some photos I recently took while on a weekend trip to San Antonio TX to visit friends.

Airplane at Salt Lake City Airport (Fujifilm X-S10, 18-55mm)