jidanni's Diary

Recent diary entries

When to flip north-south road names

Posted by jidanni on 13 August 2023 in English.

North America has a lot of streets that go “straight north and south”.

This presents a difficulty because once a road’s azimuth goes left of due north, its labels must flip to avoid becoming upside down (as the street continues curving.)

This is not usually a problem with straight parallel streets, as all will be left or right of due north, thus their labels will all either read all upwards or all downwards.

So why do the labels on Brown Avenue, in Evanston, IL USA flip back and forth, disturbingly different than its neighboring fellow north-south streets? (See and inspect its avenue name at different zoom levels.)

Ah ha, because it wavers sightly back and forth over true north! Let’s check those azimuths as we go along it:

perl -F\" -awnle 'next unless $#F==18; print "@F[-2,-4]"' full |
  sort -k 2n | gmt mapproject -Aof -o2

Anyway, “you got to draw the line somewhere” for when to flip lettering, so it’s at true north. Adding some “AI fuzz factor” would probably just complicate algorithms.

Location: Central Street Merchant District, Evanston, Evanston Township, Cook County, Illinois, 60091, United States

International Boundary Line, Rainbow Bridge, Niagara Falls US/Canada

Posted by jidanni on 5 November 2022 in English. Last updated on 26 November 2022.

I made this “brilliant essay” about the US/Canada flag positions on Rainbow Bridge, Niagara Falls.

What does it have to do with OpenStreetMaps?

Well it turns out OpenStreetMaps’ version of the US/Canada boundary is different than that of the International Boundary Commission’s.

Sure hope somebody here will fix it one day, updating OpenStreetMaps’ version with that of the Commission’s.

It’s a series of “turning points” in a river. Sorry about Ground Truth. You’ll just have to trust them.

But if you can’t trust them, who can you trust?

Location: Chippawa, Niagara Falls, Niagara Region, Golden Horseshoe, Ontario, L2G 6B2, Canada

Most cellphone GPS traces will pollute OSM

Posted by jidanni on 14 September 2021 in English.

Here we see that most of today’s cellphones’ GPS traces are “all over the parking lot,” thus will degrade the quality of OSM when making a map from them,

But yes, you could say having a path on the map is better than no path.

See also .

GitHub is great, but note, if you block somebody on GitHub, they won’t get (your) notifications:

@holmes: any final opinions?

Alas, holmes won’t have any, because he didn’t get notified. And, you, assuming blocking works the same on GitHub as it does on other platforms, will assume holmes is ignoring / blocking you, and get even more angry at him, when in fact it is you blocking him.

Same when you resolve holmes’ bug reports, pull requests, etc. He won’t know until one day some third party comments on one, if ever.

OpenStreetMap’s many teams using GitHub should be aware of this potential for software-exasperated discord.

See also: ,

(Yes, you will probably also hear less noise from (example user) holmes, but did you know that you caused him to not see the notifications he normally would of your actions?)

Yuppie map layer

Posted by jidanni on 16 May 2020 in English.

Let’s see. For Map Layers, there are
- Standard
- Cycle Map
- Transport Map
- Humanitarian
Well there needs to be an additional yuppie oriented map layer…

- Old folks’ homes
- Boring plumbing supply shops, etc.
- Fussy political boundaries, national or even school district, and associated customs offices
Yup, not rendered a single bit.

- Coffee, snack, holiday refreshment shops
Rendered extra big.

From: 內政部地政司全球資訊網
Subject: 意見信箱-回覆通知
Date: Fri, 01 May 2020 09:43:35 +0800

積丹尼 先生(小姐) 您好:

  您於 109年04月23日 寄給本司的電子郵件,提及 北屯路過界疑點為例, 追查怎麼有差異1事 一事,茲,答覆如下:


  經查本司95年所出版臺中市北區、北屯區之行政區域圖界線,係當時2區公所查對確認,迄今亦無變動,且與國土測繪圖資服務雲109年3月之鄉鎮市區界線圖層之界線一致。至於您所提門牌為臺中市北區北屯路28-1號之建物,其實際位置卻坐落於臺中市北屯區 行政區域圖內之疑義,宜由臺中市政府查明情況後,並依據相關規定辦理門牌號變更或行政區域調整作業。


敬祝 身體健康 萬事如意
內政部地政司 敬啟

Location: Beijing Village, Beitun District, Taichung, 406, Taiwan

Why I can't use JOSM, not even for one minute

Posted by jidanni on 3 March 2020 in English. Last updated on 30 August 2020.

Because its “left handed bindings” mess up my muscle memory for weeks: . (It would be fine if that was the “side of the road” that all software “drove on”, but it isn’t, and I can’t adapt, back and forth. Yes, I’m kind of weak.) Too bad they hardwired everything, not knowing about indirection. Let’s hope iD doesn’t make the same mistake.

Each imagery offset is different, and over time a patchwork of different referencing systems emerges… one big disaster, worse than “GCJ-02” (which is at least “smooth and not noticeable”.) Happens even with just one person editing. You’ll notice it when you finally join village A to village B. Editors of village A have been pulling the imagery downwards to match what they have already mapped. And editors of village B have been pulling the imagery upwards…

I hope one day, after offsets are finally no longer present in imagery, Artificial Intelligence (?) will somehow fix the mess.

Location: 基寮坑, Dongshi District, Taichung, 42351, Taiwan