Random #ThingUmbrella tip & tidbit about unit conversions: I've been sourcing materials for a larger contact printing setup for my kallitype process, incl. getting a much heavier ultra-clear glass plate than what I've been using so far.

Using the https://thi.ng/units converter with its Lisp-like domain specific language, I can easily compute the following, freely mixing compatible units with complete ease. Using the S-expression DSL is optional. There's also a normal TypeScript/JavaScript API...

```
// weight in kilograms of 48cm x 35cm x 8mm plate
(kg (* 48cm 35cm 8mm glass))
// 3.36

// or use a DIN paper size preset
(kg (* (area din_a3) 8mm glass))
// 2.4948

// calculate force
(newton (* 48cm 35cm 8mm glass earth_gravity))
32.86191

// calculate PSI (pounds per square inch) of the plate on a smaller area
// here for a 6x4" print area example
(psi (/ (* 48cm 35cm 8mm glass earth_gravity) (* 6in 4in)))
// 0.30782

// compare with a simple picture frame
(psi (/ (* 24cm 30cm 2mm glass earth_gravity) (* 6in 4in)))
// 0.03298

// ...the thicker plate causes ~10x more pressure. q.e.d.
```

Maybe someone else finds that useful. The package readme contains a lot more information about possibilities, predefined constants and examples...

#ThingUmbrella #UnitConversion #Physics #TypeScript #JavaScript #DSL #Lisp

#ReleaseThursday #OpenSourceXmas A little present (to some of you)... Been meaning to release these recent additions before the holidays, but only getting around to it now. The most important new things are these:

https://thi.ng/units now includes a Lisp-like formula DSL to combine, calculate and convert quantities and units in a much concise manner than via the normal TypeScript API (see attached examples)

https://thi.ng/pixel-io-tiff is a new package (only 2.6KB) to provide TIFF image format parsing and EXIF/GPS metadata extraction (without having to parse the image fully). Also includes format conversions for https://thi.ng/pixel buffers (grayscale 8/16bit, RGB 24/32bit), but only supports most common TIFF features (e.g. tiles, strips, uncompressed or deflate). Supports multiple sub-images... Write support will be released early next year

https://thi.ng/math now has conversions to/from fractions, using "continued fractions" for best possible precision (also includes recursion-free implementations of GCD & LCM).

https://thi.ng/binary now provides `DATAVIEW`, a JS-native DataView-like API tailored for using `Uint8Array` or vanilla JS numeric arrays (assuming the array contains u8 values) and accessors for signed/unsigned 8-64bit word sizes and little/big endian ordering.

See main #ThingUmbrella readme for other recent updates:
https://github.com/thi-ng/umbrella?tab=readme-ov-file#latest-updates

#TypeScript #JavaScript #OpenSource #DSL #Lisp #UnitConversion #TIFF #Binary #Fraction

A couple of my colleagues and I were idly chatting about #UnitConversion and we came up with this idea (crude spreadsheet rendering, sorry) for a quick approximation. We're sure it isn't an original idea, does anybody know what it's called?

This one converts between inches and centimetres. From a value in inches, trace out to the next spiral arm to approximate centimetres. From a value in cm, trace in one arm to approximate inches. Values outside of the range, use some factor of 10.

#box
#delivery
#unitConversion

http://www.saginomiya.co.jp/auto/pdf/kankei_2.pdf

kPaとkgf/cm2の関係
1kPa = 1.01972 * 10^(-2)