Re: How to handle Units of Measure
- To: mathgroup at smc.vnet.net
- Subject: [mg100475] Re: How to handle Units of Measure
- From: John Jowett <John.M.Jowett at gmail.com>
- Date: Fri, 5 Jun 2009 03:01:53 -0400 (EDT)
- References: <gvlhom$djb$1@smc.vnet.net>
You could try the Accelerator`ConstantsUnits` package, I have mentioned in previous posts: http://jowett.home.cern.ch/jowett/Accelerator/ConstantsUnits.html Then a numerical version of your example (choosing unusual frequency units just to demonstrate the power) is Z = R + I*w*L /. {R -> 10.*Ohm, w -> 300000./Day, L -> 5.*Henry} Convert[Z,Ohm] which returns (10. + 17.3611 I) Ohm A symbolic version would be Z = R + I*w*L /. {R -> rO*Ohm, w -> wD/Day, L -> lH*Henry} Convert[Z, Ohm] returning Ohm*(rO + (I*lH*wD)/86400) It all looks better in a notebook of course. John Jowett On May 28, 10:24 am, Alexei Boulbitch <Alexei.Boulbi... at iee.lu> wrote: > In this very simple example if I write > R+iwL > where R is measured in Ohms, w in s^-1, L in H, I expect that the > result is given in Ohms. > Why it doesn't happen in Mathematica ? Ho can I do to handle in a > simple way those conversions ? > Thanks > > Hi, Theodoro, > I do it this way, simple enough: > > In[30]:= R := x*Ohm; > w := z*Hz; > L := y*H; > H = Ohm/Hz; > R + w*L // Simplify > > Out[34]= Ohm (x + y z) > > -- > Alexei Boulbitch, Dr., habil. > Senior Scientist > > IEE S.A. > ZAE Weiergewan > 11, rue Edmond Reuter > L-5326 Contern > Luxembourg > > Phone: +352 2454 2566 > Fax: +352 2454 3566 > > Website:www.iee.lu > > This e-mail may contain trade secrets or privileged, undisclosed or other= wise confidential information. If you are not the intended recipient and ha= ve received this e-mail in error, you are hereby notified that any review, = copying or distribution of it is strictly prohibited. Please inform us imme= diately and destroy the original transmittal from your system. Thank you fo= r your co-operation.