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[stephen.bepko]

In my opinion (and I'm just a physicist, not a math major) the use of units should be independent of the functional form or the numerical method of integration. Simply adding identical units in the numerator and denominator of the function to be integrated changes the value of the integral. In the real world, the units should simply cancel each other out.

Not only that, but changing the flavor of the units (i.e changing from, say, length units to mass units) in the numerator and denominator ALSO changes the value. Make the units, say, kilometers, then change them both to kilograms- the integral evaluates differently.

Does MathCad change the integration algorithm based on the type of units used ?? That would be special... Some programmer would have to go to a lot of trouble for that implementation.

Remember - the units are IDENTICAL in the numerator and denominator, resulting in a dimensionless function !

[StuartBruff]

On 5/6/2010 11:56:20 AM, sbepko wrote:
== Does MathCad change the integration algorithm based on the type of units used ?? That would be special... Some programmer would have to go to a lot of trouble for that implementation.
== Remember - the units are IDENTICAL in the numerator and denominator, resulting in a dimensionless function !

AFAIA, Mathcad does indeed cancel out identical dividing units. I've just checked on my M13 and it doesn't make any difference, to the result of integrating cos between 0 and 4, if I add an kg/kg or km/km inside.

Could you please post a worksheet which gives an example of the problem you are seeing? Order might be important if standard floating-point round-off errors are being introduced before the actual 'division' is performed (eg, (kg*expression)/kg v (kg/kg)*expression)

Stuart

[RichardJ]

On 5/6/2010 2:04:47 PM, stuartafbruff wrote:

>Could you please post a worksheet which
>gives an example of the problem you are
>seeing?

This was a mis-post. See this thread:

http://collab.mathsoft.com/~Mathcad2000/read?134383,99

Richard

[ptc-1368288]

On 5/6/2010 11:56:20 AM, sbepko wrote:
...
>Remember - the units are
>IDENTICAL in the numerator and
>denominator, resulting in a
>dimensionless function !

________________________________

Certainly NOT dimensionless !



jmG