Re: units.h

["Mark M. Ito" <marki@jlab.org>]

Matt,

I appreciate your trust in my arithmetic ability, but I really think 
that I trust you much more than I trust myself. ;-)

  -- Mark

Matthew Shepherd wrote:
>
> Here's the units.h file for CLEO.  Note that the unit choices are 
> somewhat different from what Mark is proposing.  I'll let Mark 
> multiply and divide by the requisite factors of 10 and put into the 
> repository in an appropriate place.
>
> -Matt
>
>
> #if !defined(EXPERIMENT_UNITS_H)
> #define EXPERIMENT_UNITS_H
> // -*- C++ -*-
> //
> // Package:     Cleo
> // Module:      units.h
> //
> // Description: These are just a few definitions for specifying units and
> //              keeping things consistent.
> //
> // Usage:
> //    It's just like writing up homework!  Specify your units, and 
> it'll all
> //    work just dandy.  If a length is 3.5 cm, it becomes 3.5*k_cm.  
> If it's
> //    1.2 in, it becomes 1.2*k_in.
> //
> //    If, on the other hand, something passes a number back to you in, 
> say,
> //    grams per cubic centimeter, you would *divide* by k_g_per_cm3 to 
> get it
> //    in the correct CLEO III units.  Think of the CLEO III units as
> //    dimensionless, and this makes sense.
> //
> //    Simple, isn't it?
> //
> //    One final note:  "k_degrees" refers to angles, not temperature.  
> Since
> //    there are no multiplicative conversions between the common 
> temperature
> //    units, this shouldn't cause much confusion.
> //
> // Author:      Michael Marsh
> // Created:     Tue Jan 20 12:06:31 EST 1998
> // $Id: units.h,v 1.6 2001/12/18 20:48:20 lkg Exp $
> //
> // Revision history
> //
> // $Log: units.h,v $
> // Revision 1.6  2001/12/18 20:48:20  lkg
> // added time units
> //
> // Revision 1.5  1998/11/24 19:35:49  mkl
> // turned float into double for standard types and units
> //
> // Revision 1.4  1998/07/03 17:29:48  marsh
> // Changed units of energy to GeV.  Added units for magnetic field (kG).
> // Added more units, such as keV and radians, and more constants to 
> convert
> // from CLEO units to all units with constants.
> //
> // Revision 1.3  1998/05/14 19:58:05  marsh
> // Added millimeters, microns, and mils.
> //
> // Revision 1.2  1998/05/07 22:26:06  marsh
> // Renamed the constants to be more readable.  This was in response to 
> input
> // that people didn't like the old names, such as kM, which looked 
> like it
> // might be kilometers, but was in fact meters.
> //
> // Revision 1.1  1998/04/09 19:48:50  marsh
> // New in repository.
> //
>
> // system include files
> #if defined(EXCEPTION_CLASH_WITH_MATH_H_BUG)
> #define exception _math_bug_
> #include <math.h>  // required for trigonometry and fabs
> #undef exception
> #else
> #include <math.h>  // required for trigonometry and fabs
> #endif
>
> // user include files
>
> const double k_in_to_cm = 2.54;
>
> const double k_m  = 1.0;
> const double k_cm = 0.01;  // lengths are in meters
> const double k_mm = 1.0E-3;
> const double k_um = 1.0E-6; // microns
> const double k_in = k_in_to_cm * k_cm;
> const double k_mil = k_in * 1.0E-3;
> const double k_to_m = 1/k_m;
> const double k_to_cm = 1/k_cm;
> const double k_to_mm = 1/k_mm;
> const double k_to_um = 1/k_um;
> const double k_to_in = 1/k_in;
> const double k_to_mil = 1/k_mil;
>
> const double k_kg = 1.0;
> const double k_g  = 0.001;
> const double k_u  = 1.6605402E-27;
> const double k_to_kg = 1/k_kg;
> const double k_to_g = 1/k_g;
> const double k_to_u = 1/k_u;
>
> const double k_kg_per_m3 = 1;
> const double k_g_per_cm3 = 1000;  // density is in kg/m^3
> const double k_to_kg_per_m3 = 1/k_kg_per_m3;
> const double k_to_g_per_cm3 = 1/k_g_per_cm3;
>
> const double k_Pa  = 1; // pressure is in pascals
> const double k_atm = 101325;
> const double k_to_Pa = 1/k_Pa;
> const double k_to_atm = 1/k_atm;
>
> const double k_GeV = 1; // energy is in GeV
> const double k_MeV = 1.0E-3;
> const double k_keV = 1.0E-6;
> const double k_eV = 1.0E-9;
> const double k_to_GeV = 1/k_GeV;
> const double k_to_MeV = 1/k_MeV;
> const double k_to_keV = 1/k_keV;
> const double k_to_eV = 1/k_eV;
> const double k_to_J = 1.60217733E-10;
> const double k_J = 1/k_to_J;
>
> const double k_kGauss = 1;
> const double k_Gauss = 1.0E-3;
> const double k_Tesla = 10;
> const double k_to_kGauss = 1/k_kGauss;
> const double k_to_Gauss = 1/k_Gauss;
> const double k_to_Tesla = 1/k_Tesla;
>
> const double k_radians = 1; // pretty much everything uses radians
> const double k_degrees = M_PI / 180;
> const double k_to_radians = 1/k_radians;
> const double k_to_degrees = 1/k_degrees;
>
> const double k_psec = 1; // Cleo has typically used picoseconds
> const double k_nsec = 1.0E3;
> const double k_usec = 1.0E6;
> const double k_msec = 1.0E9;
> const double k_sec  = 1.0E12;
> const double k_to_psec = 1/k_psec;
> const double k_to_nsec = 1/k_nsec;
> const double k_to_usec = 1/k_usec;
> const double k_to_msec = 1/k_msec;
> const double k_to_sec  = 1/k_sec;
>
> #endif /* EXPERIMENT_UNITS_H */
>