4 ms·

> because π is not representable is their system (typically base-2 or base-10 floating-point). Casio scientific calculators do have an internal representation

by ronaldx 13y ago

> because π is not representable is their system (typically base-2 or base-10 floating-point). Casio scientific calculators do have an internal representation of π (it's treated differently from the closest possible typed value) and very nuanced representations of numbers in general. As you say, this is where calculator apps almost inevitably fail - representing numbers properly is really crucial to the UX, and floating point numbers are not sufficient.

csmuk 13y ago
Spot on. This is one reason I still use my 50g - it uses decimal internal representation with known precision on every operation. Casios are a mess. They are actually made my Kinpo which do a shitty job of pretty much everything. The notable exceptions being the FX991MS and Fx5800P which are very very close to my 50g (which was laboriously tested on paper before I trusted it)
- chinpokomon 13y ago
  I favor the 48GX with several modifications. I have a library that gives me 5 stack lines, but also shows a symbolic representation. In other words, typing "5 6 /" is represented as "5/6" rather than a decimal equivalent. If you multiply that by 2, my calculator maintains the symbolic representation as "(5/6)*2". By retaining values as symbolic representation for as long as possible, when you finally evaluate, it will result in "5/3". This is great for when things cancel out and it allows me to carry precision further since I'm not working with approximations. I can also request the decimal representation at any time. This is what no other calculator app is giving me.
  - csmuk 13y ago
    The 50g already does that as it has a built in CAS so symbolic is default. This are represented in their rational form or with respect to pi. 50g is basically a 48GX emulator with 400MHz ARM core that emulates Saturn, MetaKernel and a CAS. Goes like lightning. Oh and a bigger screen so you get 7-9 stack lines. Also you can use SD cards as ports. Mine has 256Mb of Flash. Eats a set of batteries once a month but it's worth it for the power. I can create a symbolic list with 50,000 entries in quite happily on the device then do all standard two-variable stats on it in 1-2 seconds.

by ronaldx 13y ago

csmuk 13y ago

Spot on. This is one reason I still use my 50g - it uses decimal internal representation with known precision on every operation. Casios are a mess. They are actually made my Kinpo which do a shitty job of pretty much everything. The notable exceptions being the FX991MS and Fx5800P which are very very close to my 50g (which was laboriously tested on paper before I trusted it)

chinpokomon 13y ago
I favor the 48GX with several modifications. I have a library that gives me 5 stack lines, but also shows a symbolic representation. In other words, typing "5 6 /" is represented as "5/6" rather than a decimal equivalent. If you multiply that by 2, my calculator maintains the symbolic representation as "(5/6)*2". By retaining values as symbolic representation for as long as possible, when you finally evaluate, it will result in "5/3". This is great for when things cancel out and it allows me to carry precision further since I'm not working with approximations. I can also request the decimal representation at any time. This is what no other calculator app is giving me.
- csmuk 13y ago
  The 50g already does that as it has a built in CAS so symbolic is default. This are represented in their rational form or with respect to pi. 50g is basically a 48GX emulator with 400MHz ARM core that emulates Saturn, MetaKernel and a CAS. Goes like lightning. Oh and a bigger screen so you get 7-9 stack lines. Also you can use SD cards as ports. Mine has 256Mb of Flash. Eats a set of batteries once a month but it's worth it for the power. I can create a symbolic list with 50,000 entries in quite happily on the device then do all standard two-variable stats on it in 1-2 seconds.