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By Lydia_R · Posted
Andy and I just had another discussion on this which turned to how pi is computed. I kept on pressing for the measuring a big wheel method and he kept driving this idea home that measuring like that is inaccurate. We agreed to disagree on that, but then he googled how pi was originally computed. I have never looked this up because I tend to not want to get an answer out of a book like that because I enjoy the challenge of working things out on my own. The answer he found said that Archimedes did it by crunching the math of a 96 side polygon. And then I immediately thought, YES! When I was on the streets of Seattle in January of 2004 and got interested in studying trigonometry, I went to the library and there as a little green book called Plane Trigonometry with a canvas cover and then next to it or nearby was a slightly bigger blue book with a canvas cover on Calculus. I opened the calculus book and it said that calculus is the study of two different things. One of them is the measurement of an irregular area through methods of exhaustion. So that is definitely what Archimedes was doing there. And it makes sense that you can do that and wind up with an answer that it is within the range which you can call the tolerance. I got interested in coding the math of a pinball machine in 2013, so I thought about it for a few minutes and decided that I needed to know the intersection of two lines. So I Googled that and it came back with a small linear algebra equation which I was then able to code into a computer pinball machine in about 300 hours. The idea of this type of collision detection is that there are only points and the lines between them. There are no true curves in the game. I was using this process of taking an artist's drawing of a maze and using Adobe Illustrator to turn it into vector graphics (SVG) and then they had some special function that would reduce all the curves in the SVG data to a series of straight lines. Then I would consume the SVG data in my code and display the raster image. It worked great and of course I was using a polygon for the ball. With that huge amount of vector data, I wound up having to write special code to break that vector data into buckets within an array so that the collision detection wasn't working on all the lines at the same time because that would just bog the computer down. I had to write and inRange() function to determine what sector(s) the ball was in and then grab the vector data for what could possibly be a collision. I would compile those buckets (array) at runtime when the maze was opened. The dependency on Adobe Illustrator was the death of the project. The conversion process was tedious and the artist wasn't up to doing that work. I researched other code to do it and never got anything that worked. I dated a transwoman last year who did engineering work for a machine vision company and that sparked some new ideas. The subject of machine vision has been on my mind for 20 years, but I hadn't quite figured out how to start coding it. Then I realized last year that the way to do it would be to make a QR code reader. You could start out with just like a 4x4 QR code pattern. You take an image of it. Or, you know, I guess those registration points in the corner are important, but to start coding, you could start with a perfect image of a 4x4. Then you would lay a theoretical grid on top of it. Then you would iterate over the grid and find out whether the pixel dead center in each square is black or white. Then you would look at all the pixels around it and then average them and compare them to the one pixel in the center. If the average of the outer pixels matches the center pixel, then you have a good estimate going. So it would be that sort of thing. But then to actually extend that to interpret lines at any angle... Well, that would be very challenging work. It's all very interesting stuff and if I live long enough, I'd like to start working on that. I'm 53yo and this is kind of a hobby at this point. I did good with going from having absolutely nothing on the streets to making all this happen and buying a house 10 years after I got off the streets in 2014. I've been able to pay for 100% of my gender out of pocket so far, so I get a kick out of the fact that writing math on paper on the streets allowed me to do that. I've made just over $1 million in my life, so it's not like I got rich off of that at all. Over the span of my 35 year career, I've averaged about $35,000/year. I live an excellent life though and all I really care about is having good food and time to cook it. And having some time to play some nice piano. Anyway. I put this in the story section. It's an autobiographical math story. I've written all kinds of stuff about my life, but I tend to draw it back to a math education lesson. Perhaps that turns some people away. I always wish that our politics would focus more on engineering and less on the social issues. I think we really take engineering for granted in our modern societies. -
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By Mars Hiroshi · Posted
Thank you very much! This helps. The binder is too big, but I'm not good at sewing TwT -
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By Adrianna Danielle · Posted
I oiled this one regularly.It was getting weak and quit finally this morning.Took the air tool fitting off and told the scrap metal guy that comes in to pick up the scrap he can have it -
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By Ivy · Posted
Thanks But honestly, I don't understand a thing in this thread. LOL -
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By Ashley0616 · Posted
calmness: : a period or condition of freedom from storms, high winds, or rough activity of water : complete absence of wind or presence of wind having a speed no greater than one mile (1.6 kilometers) per hour see Beaufort Scale Table : a state of tranquility -
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By Lydia_R · Posted
And I love your new profile pic @Ivy! Wow, looking great! -
By Jani · Posted
I hadn't heard about the John Sebastian invite. Interesting. He certainly would have blended in well with the other three.
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