∫ntegrabℓε ∂iﬀerentiαℓs · unorganised notes, code, and writings of random topics

Black and White

September 27, 2024 blog math

There is no black and white. Human perceived black for no visible light, and some composition of light wavelengths is perceived as white. To measure the grayscale, we want to quantify what is black and what is white. [more]

Timezone in Python

April 19, 2024 blog code

The UNIX epoch is always in UTC. There’s no such thing as local epoch. To get the epoch in command line, you do date +%s, or in Python, time.time(). It doesn’t matter if time.localtime() and time.gmtime() are different, the epoch is universally consistent across timezone. [more]

concurrent.futures in Python

February 9, 2024 blog code

The Python standard library concurrent.futures is the easiest way to run parallel jobs in the best-effort manner. In case the heavy jobs are run off-interpreter (e.g., NumPy) using the thread pool from concurrent.futures can give you some noticeable performance benefit. [more]

Photo Color Adjustment

January 2, 2024 blog code

Photos are matrices of pixels. Each pixel can be a tuple of RGB values (the most common) or other color spaces such as Lab or HSV. RGB is great for its additive nature. HSV, however, considered hue as an angle in some arbitrary order. It is better than RGB if... [more]

Peng et al (2023) YaRN: Efficient Context Window Extension of Large Language Models

November 9, 2023 paper

This paper studies the positional encoding in large language models, since it is the factor that needs to change if we want to support a longer context length than it was pretrained. The original transformer model’s position encoding scheme was called the absolute sinusoidal position encoding. Then, there are models... [more]