Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

When doing engineering calculations it is great convenience to do have software that keeps track of units.

Example when calculate something trivial as stress:

$\sigma = \frac FA$

And be able to write:

$\frac {1kN}{1m*1mm}$ and get the answer in MPa

This is by nature a poll thread that i know is frowned upon on StackOverflow, is it going to be closed?

share|improve this question
2  
One of the top search results for "units software" is the appropriately named GNU Units, which lets you say "You have: ten furlongs per fortnight / You want: kilometers per hour" and tells you "0.0059871429". –  Rahul Nov 1 '12 at 9:08
    
Write that as an answer, I guess F# is an answer too though I was looking for a GUI app. –  Johan Larsson Nov 1 '12 at 9:11

7 Answers 7

I'll throw my hat in the ring too. Maxima [1] has an add-on package ezunits which carries out various dimensional operations. Quantities can be symbolic (e.g. x meters per year) as well as numerical. The notation is, I hope, convenient: single left quote to indicate units, double left quote to indicate conversions. For the given example:

load (ezunits);
F : 1 ` kN;
A : 1 ` m * 1 ` mm;
sigma : F/A `` MPa;
  => 1 ` MPa

There's more to be said, but I'll let it be enough for now. Disclaimer: I wrote the ezunits package.

[1] http://maxima.sourceforge.net

share|improve this answer

You might be interested in Frink.

It has an interpreter that you can download as a desktop app. It also has a web interface, which lets you type

in  >> 1 kN / (1 m * 1 mm)
out >> MPa

to get

result >> 1 MPa

There is a list of sample calculations covering a wide variety of physical applications.

share|improve this answer

There is SpeQ Mathematics for Windows environments. It is probably more of what your looking for.

http://www.speqmath.com/index.php?id=1

share|improve this answer

One of the top search results for "units software" is the appropriately named GNU Units, which lets you say

You have: ten furlongs per fortnight
You want: kilometers per hour

and tells you "0.0059871429".

share|improve this answer
    
I feel a little silly posting an answer that's basically "I googled your question and got this", but there it is. –  Rahul Nov 1 '12 at 15:47
    
Can still be some use with a comprehensive list. I up-voted. –  Johan Larsson Nov 1 '12 at 16:05

MathCad handles units in a nice way but it is too expensive for home use.

share|improve this answer

I'll add F# to the list.

Floating point and signed integer values in F# can have associated units of measure, which are typically used to indicate length, volume, mass, and so on. By using quantities with units, you enable the compiler to verify that arithmetic relationships have the correct units, which helps prevent programming errors.

share|improve this answer

Google Calculator does this nicely for units it knows about:

enter image description here

And you can't beat the price.

share|improve this answer
    
I up-voted but will leave the question open. –  Johan Larsson Nov 1 '12 at 9:03

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.