Mathcad 15 trim units

[qm]

I have some empirical formulas to enter in Mathcad 15, in which the values should be inputted without units.

Is there any way to input them other that dividing the variable to his unit?

Example:

a=1m

b=2kg

I don't want to input:

c=a/1m + b/1kg = 3

I want something like:

c = "trim unit" (a+b) = 3

Note:

I want to keep the units for a and b definitions.

I don't want to define other variables.

Thanks

[StuartBruff]

You could use the SIUnitsOf function, eg [a+b]/SIUnitsOf([a+b]). 

Do you want to actually use the units or are they just for documentation? If the latter then you could turn off units and just define m:=1 and kg:1, then you wouldn't need to divide by anything.

Stuart

[Fred_Kohlhepp]

I did that once.  It seemed like a neat solution to this exact type of problem!

Then Tom Gutman pointed out that my mis-labeling a variable unit was what was trashing my ODE solution.  As Tom pointed out, "de-uniting" a variable has its own set of problems.

We all wrestle with dragging old printed text equations with unexplained numerical constants (often a unit conversion multiplier) into Mathcad.  I get extremely suspicious when the equation will not unit balance.  (Power is shaft torque times shaft speed.  If I multiply any set of torque units times any set of angular velocity units I will get units of power--the equation is unit balanced.)

I like Richard's suggestion, take the time to set up a valid unit balanced formula.

[RichardJ]

You need to modify the empirical formulas. Divide each input quantity in the formula by the expected input units, and multiply the entire formula by the expected output units. Then you have a unit aware formula that can be called with any units you like, and will return a correct result with units.