Feature request: unit tracking / translation

[Former user]

Originally reported on Google Code with ID 153

e.g. "(1 mile / 30 seconds) in mph" => "120 mph"

Most people reading this will have seen it done by google calculator before
- it's really useful there, and combined with speedcrunch's variables,
functions, quickness and offlineness it'd be all of the awesome :)

Cheers,
Jeff (aka je4d)

Reported by jefford on 2008-02-10 22:35:47

[Former user]

``` this will have to wait until the parser is ready ```

Reported by `wolf.lammen` on 2008-02-22 15:08:28

[Former user]

``` Bobluck wants to be able to define his own units. See here: http://groups.google.com/group/speedcrunch/browse_thread/thread/8fb487d25c526fa1 ```

Reported by `wolf.lammen` on 2008-03-26 10:53:46

[Former user]

``` This is an option that interests me too. I'm a mechanical engineer and use units on a daily basis. In my opinion it should look something like this: x=40[N] # x is 40 Newton l=1[m] # l is 1 meter T=40[Nm] # Speedcrunch calculates that torque is 40 Newton*meter I use the S.I. standard ( http://en.wikipedia.org/wiki/S.I. ) for the notation of units. And most people I know put units between [ ]. Ofcourse it must be possible to change the units in the answer. For example: the units in the answer above should be displayed in [Nmm] in stead of [Nm].

I hope this feature will be added in the near future.

Greetings, Walter ```

Reported by `wr.schrotenboer` on 2008-05-02 17:08:23

[Former user]

``` I liked wr.schrotenboer's unit definitions (between []). But regarding his last sentence I can only say "I wish we were at lelst ten of us and all payld to work full-time on the application" :) ```

Reported by `helder.pereira.correia` on 2008-05-02 17:29:03

[Former user]

Reported by `helder.pereira.correia` on 2009-05-05 23:38:27 - Labels added: Type-Enhancement, OpSys-All, Component-Logic, Usability - Labels removed: Type-Defect

[Former user]

``` Issue 369 has been merged into this issue. ```

Reported by `helder.pereira.correia` on 2010-12-29 19:05:36

[Former user]

``` I believe this type of function is called "Dimensional Analysis" I can not say much about it but here is a guy who can:

http://www.youtube.com/watch?v=PmJV8CHIqFc

It would be extremely useful if we could do stuff like

89 (km) / 7,2 (L) = ? (MPG)

or for example

1,21(M) + 12,7(k) = 1 222 700

or

12V / 1kOhm = 12mA

or

12 ft / 10 s = 1,2 ft/s ANS (m/s) = 0.36576 m/s

I wish the issue was moved up a notch in importance. ```

Reported by `keskinvib` on 2011-10-30 21:26:17

[Former user]

``` Hi everybody!

I think this can be done in an easy way. Actually I used to work with Windows XP PowerToy Calculator, but since it does not work fine on Win 7 (and has some bugs), I had to search for another good calculator, which is speedcrunch.

The way is: using predefined constants. For the moment I am doing it by means of variables. For example:

cm_in = 0.3937 in_cm = 2.54

So when I want to make a conversion I just multiply:

Ex 1) 5cm to inches: 5*cm_in = 5*0.3937 = 1.9685 in

Ex 2) 10in to inches: 10*in_cm = 10*2.54 = 25.4 cm

That's it.

The suggestion would be saving the conversion values into the constants list, conversions category. Or creating a new tab for conversions, then add there all those values. Maybe you could make here type categories. I think this implementation is easy and does not need changing the parser.

```

Reported by `treww5` on 2012-08-12 16:51:26

[Former user]

``` @reww5 The problem is that there are too many combinations with the method you suggested, e.g. cm_in m_in km_in and so on, maybe thousands of them among all units. Also, multiplying a value by a constant works but it's not so intuitive. ```

Reported by `helder.pereira.correia` on 2012-08-12 19:06:30

[Former user]

Three quick points:
(1)  GNU Units (http://linux.die.net/man/1/units, but also available via Cygwin) comes
with a database of conversions (/usr/share/units.dat) which could be used (or Units
could be used as a library). 
(2)  There are always issues w/ representation of constants and units based on different
character encoding.  I agree it would be great to keep track of the units.  I would
suggest looking at the Unified Codes for Units of Measure (UCUM) for how to represent
units unambiguously in a fashion designed to support computability and communication.
 I think those who are using UTF8 with a proper font should have the option to see
the typical print form (e.g. for SI) as an option.  It probably would not be too hard
to have a UTF8 file w/ UCUM mapped to SI preferred display. 

UCUM discusses issues and conversions to ISO 2955 and ANSI X3.50.

For example, temperature can use different glyphs.  °C (U+00B0 and U+0043) can also
be conveyed using ℃ (U+2103). UCUM would use [Cel] (or [CEL] for a case-insensitive
representation.

(3)  prefixed units (e.g. KB, MB, TB) need to have some attention and be treated internally
such that exponents don't get lost!  I specifically mentioned KB, MB and TB since these
are actually bad examples, and knowing what the user really means is important.  Do
they mean the EU/NIST/IEC/IEEE definition of 1 kB = 1000 (10^3--or 10³ depending on
encoding/font support) bytes, or do they really mean a kibibyte which is 1024 bytes
(2^10 aka 2¹⁰).

Reported by kevin.coonan on 2013-08-26 23:36:09

[Pol Welter]

Duplicate of #488.