File Exchange

image thumbnail

DIMENSION - tagging values with units

version 1.0.0.0 (32.6 KB) by Nathan Thern
Class for tagging values with units. Provides for transparent conversion, unit checking & combining.

1 Download

Updated 07 Feb 2005

View License

Joe engineer's script works in radians and meters. The lab data files are in degrees and inches and the drawings are in mm. Joe tags everything with dimensions and never worries again about conversions. He even discovers a bug where a value he thought represented area really represents distance.

Whirlwind Tour:
>> side = dimension(500,'m')
side = 500 m
>> height = dimension(2.1,'km');
>> height + side
ans = 2.6 km
>> side + height
ans = 2600 m
>> height > dimension(1,'mi')
ans = 1
>> convert(side*height,'acre')
ans = 259.461 acre
>> msquared = dimension(1,'m',2)
msquared = 1 m^2
>> convert(side*height,msquared)
ans = 1050000 m^2
>> speed = dimension(60,'mi','hr',-1);
>> value(speed)
ans = 60
Or
>> speed.value
ans = 60
>> convert(speed,'kph')
ans = 96.5606 kph
>> ubase(speed)
ans = 26.8224 m s^-1
>> ubase(dimension(1,'btu'))
ans = 1055.06 kg m^2 s^-2
>> convert(height,'kg')
??? Error ==> units are incompatable
>> height + speed
??? Error ==> units are incompatable
>> speed * dimension(1.5,'hr')
ans = 90 mi
>> thickness = dimension([1,2;3,4],'in');
thickness = 1 2
3 4 in
>> thickness(2,1)
ans = 3 in
>> [ thickness [ side/1000; height/1000 ] ]
ans = 1 2 19.685
3 4 82.677 in
>> thickness'
ans = 1 3
2 4 in
>> angle = dimension(30,'deg');
>> tan(angle)
ans = 0.57735
Any value can be used as an argument to DIMENSION:
>> i_time = dimension(1*i,'s');
Users can define their own units based on previously defined units or redefine existing units:
>> frlng = dimension(220,'yd');
>> add_unit(frlng,'furlong');
>> convert(height,'furlong')
ans = 10.439 furlong
>> add_base(dimension, 'beaut');
>> add_unit(dimension(.75,'beaut','joule',-1),'tnt');
>> ubase(dimension(700,'tnt'))
ans = 525 beaut s^2 kg^-1 m^-2

Some defined units:
s, sec, min, hr, dy, wk, yr, mon, millenium
m, cm, mm, a, km, ft, in, mil, yd, mi, nm, ly, au, parsec
r, radian, deg, arcmin, arcsec, grad, cycle, rev
kg, gm, mg, tonne, lbm, oz, slug, ton, amu
k, kelvin, rankine
amp, ma
mole, mol
bit, byte, kB, MB, GB, TB
cd, candle
dollar, $, cent
cc, l, ml, gal, qt, floz
kph, knot, mph, c
Hz, KHz, MHz, GHz, rpm
nt, dyne, lb, lbf
joule, erg, cal, btu, ev, mev, kwh
sr, coulomb, ftlb, watt, gray, farad, ohm, mho, v, henry, tesla, gauss, wb

This is beta software and still in the bug-killing stage. Everything shown above works correctly, though.

Cite As

Nathan Thern (2021). DIMENSION - tagging values with units (https://www.mathworks.com/matlabcentral/fileexchange/6850-dimension-tagging-values-with-units), MATLAB Central File Exchange. Retrieved .

Comments and Ratings (3)

Jock Christie

This is a great program.
Very very helpful.

Only comment is that it is (sometimes) overly rigid about unit names.
It should treat watt=Watt=Watts the same.

The Author

I guess the primary difference from umat is that you can find it with a search on "units" or "dimensions" :-)
I had no idea umat even existed, and will take a close look at it.

- -

how does this compare to umat class?

MATLAB Release Compatibility
Created with R13SP1
Compatible with any release
Platform Compatibility
Windows macOS Linux
Categories

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!