Nostr notes by cmgrowell

I use double precision for everything (64 bit). A lot of it is ...

2026-08-25T18:15:08Z

In reply to nevent1q…84ay
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I use double precision for everything (64 bit). A lot of it is more related to how much the slope changes, so there are triggers to add control points based on change in curvature angle as you travel down the curve. If the slope changes too much, then you add a break point, etc. You can get in trouble saving data to ascii file formats if you don't write using enough precision. I think I usually use something like 12 digits for that.

I'm sure there are more formal ways to explain it. I'm more of a hack trying to keep this stuff running, based on my predecessor's algorithms. I'm starting to switch some of the complicated CAD operations over to Open Cascade, but it is nice to have our own in-house kernel for simpler things.

I learned it to 7 digits in engineering school. Now I write ...

2026-08-25T17:35:10Z

In reply to nevent1q…3q9a
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I learned it to 7 digits in engineering school. Now I write geometry creation related software for computational physics solvers and we have it set to 20 digits. The applications people don't like it if there are geometry inaccuracies when they are creating cell sizes in the 1e-6 or smaller range. Usually the issue is not PI, it is the sampling rate used to create the b-spline arc, etc. But, I don't want to introduce any other sources of possible error. The Fortran people would define it as a constant at the top of every file, and it would often be a different precision in each file.

This brings back memories. We went to the Kinetic race they had ...

2026-05-25T00:53:01Z

In reply to nevent1q…mnwz
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This brings back memories. We went to the Kinetic race they had in Ventura County a few times when the kids were young. Always fun. I forgot about it. Apparently it was discontinued in our area back 2016.

Named after Albertson Ranch and Fred Albertson. Apparently, a car ...

2026-05-20T01:12:17Z

In reply to nevent1q…739w
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Named after Albertson Ranch and Fred Albertson. Apparently, a car dealership owner in the LA area who bought the ranch from William Randolph Hearst in 1943. Most of it became Westlake Village. Not the same as the grocery store chain. We also have a Hidden Valley around here, but I don't think that is related to the salad dressing.

Apparently the four hour window for shutting off our power that ...

2025-01-23T16:36:36Z

Apparently the four hour window for shutting off our power that started at 1pm yesterday extended to 8am today.

They get worse than that. ...

2024-12-25T01:17:55Z

In reply to nevent1q…sd6q
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They get worse than that. https://pezcyclingnews.com/features/have-time-trail-helmets-just-gone-too-far/

At More Mesa it was more like very fine dirt or dust. I use a dry ...

2024-11-10T15:20:47Z

In reply to nevent1q…prwn
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At More Mesa it was more like very fine dirt or dust. I use a dry chain lube that doesn't attract grit so didn't notice any issues, it at least any more than normal.

I rode a little part of it a few weeks ago while waiting for my ...

2024-11-10T00:39:04Z

In reply to nevent1q…umgc
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I rode a little part of it a few weeks ago while waiting for my wife to arrive at the SB airport. I parked at Goleta Beach Park and used it to get over to More Mesa and rode my mountain bike on the trails there. Definitely nice to have it and plenty of people were using it. Nice for the UCSB students, too. #BikeTooter

My mom had one of those. I wonder if we still have it in the ...

2024-11-08T00:23:56Z

In reply to nevent1q…43jq
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My mom had one of those. I wonder if we still have it in the family somewhere. She would use it to listen to BBC radio in the evenings. Her and my dad moved to the US east coast from the UK in the early 60s, so it was her way of keeping touch with the news at home.

How about $18/mo for heated seats. New cars are already crazy ...

2024-10-17T12:26:08Z

In reply to nevent1q…32v6
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How about $18/mo for heated seats. New cars are already crazy expensive. I don't think the BWM subscription ideas went over too well, but look at what the airlines have done with all the extra fees. Our Tacoma came with maps, but it costs hundreds to update it at the dealer, so we've never done that. Definitely makes you want to keep your old cars running.
https://www.theverge.com/2022/7/13/23206999/car-subscription-nightmare-heated-seats-remote-start

My youngest and his friends are actually sewing quite a lot these ...

2024-10-14T14:38:19Z

In reply to nevent1q…rr35
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My youngest and his friends are actually sewing quite a lot these days, more than I ever did. He has essentially had sewing parties at our house, and this is a kid who is a bit of a gear-head. They mostly modify thrift store finds, like these pants, that I think he turned into shorts. He even signed his name using stitching. Strangely enough he has a friend from the bike league that lives elsewhere who is doing similar things (shown on instagram) and they never discussed it with each other. Not sure if it is a trend.