DimVar

A class for handling dimensioned variables in Matlab

DimVar is a class is for handling dimensioned quantities in Matlab.
It is designed to be a "stand-in" replacement for numeric data in Matlab that carries units and checks them during normal operations.
For example, you could use it to calculate conduction with mixed units as:
k = DimVar(4,'BTU-in/hr-ft^2-F');
L = DimVar(5,'mm');
A = DimVar(10,'cm^2');
DT = DimVar(500,'R') - DimVar(200,'K');

Q = k*A/L*DT;

where in this case the units are carried through to get Q in Watts. It also checks
for unit validity in math operations, so the following would generate an error:

x = k + L

since the units of k and L are different. However,

x = L + sqrt(A);
y = exp(-x/L);
V = A*L;

would be allowed.

The rules for writing the unit string are:
* Use a single solidus (/) as the separator between numerator and denominator.
* Use hyphens (-) to separate individual unit components
* Indicate powers either with or without a '^' (m^3 or m3)
* Indicate inverse units as either 1/x or x^-1
* Temperatures will be treated as absolute unless you add the optional 'Relative' argument, as in

DT = DimVar(10,'C','Relative')

otherwise the 10 C value will be converted to 283.15 K rather than 10 K. You can also deal with it by using the subtraction, so

DT = DimVar(10,'C') - DimVar(0,'C')

The most up-to-date version of this class is hosted on Github at:
http://github.com/tgvoskuilen/MatlabTools