Lydia's notes

We formed a team named Stardial and published our first website: Star Path Viewer. This is an open-source web application designed for academic research. This astronomical tool allows users to trace the path of any planet or star across the sky based on a chosen date in either the Gregorian or Julian calendar, spanning millennia into both the past and the future.

Compared to other existing tools, Star Path Viewer provides more precise information on star positions and rising/setting times, which is crucial for historians when dating historical events by correlating astrometric data with historical records. The tool also enables future prediction of star paths, aiding users in planning astronomical observations.

The star search is compatible with Chinese star names. It is a valuable function for historians of science studying ancient Chinese archives and astronomy.

Check out the GitHub repository for more infomation.

Limit the memory usage

It was annoying that WSL2 was always eating up my poor RAM. The following solution worked. [Reference]

My distribution is:

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> wsl -l -v
  NAME            STATE           VERSION
* Ubuntu-18.04    Running         2

Create a configure file named .wslconfig in your user directory in Windows.

Open PowerShell as administrator, shutdown WSL2 and edit the file:

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> wsl --shutdown
> notepad "$env:USERPROFILE\.wslconfig"

For me the content is:

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[wsl2]
memory=2GB
swap=0

Pandas 的 read_table (官方文档) 和 read_csv (官方文档) (指定分隔符的情况下两者无区别), 有关键字 sep= (read_table 默认为 sep='\t', read_csv 默认为 sep=',').

但当需要指定多个空格的情况下, 指定 sep='\s+' 可能无法被正确识别.

Python 自带一个存取 dict 到二进制文件的工具 pickle, 支持数值型的 key (numpy.savez 和 numpy.savez_compressed 只支持字符串作为 key).

用法:

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import pickle
# 存入
pickle.dump(data, open("filename.p", "wb"))  # type(data): dict
# 读取
data = pickle.load(open("filename.p", "rb"))  # 返回一个 dict

目的是从交互环境调用脚本产生的变量, 可用于调试脚本和测试数据等等.

比如当前目录下有一个包含如下内容的脚本:

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#!/usr/bin/env python
a=1
print('a =', a)