NAME: 
  dewp
 PURPOSE: 
  Compute dew point temperature give temperature and relative humidity
 DESCRIPTION:
 CATEGORY:
  Miscellaneous
 CALLING SEQUENCE:
  dewp,temp,rh,dp,CELCIUS=celcius
 INPUTS:
     temp - Air Temperature
     rh   - Relative Humidity
 OPTIONAL INPUT PARAMETERS:
     celcius - Flag, if true, all temperatures in Celcius, otherwise Farenheit
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
     dp   - Dew point temperature
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by: Marc W. Buie, Lowell Observatory, 1995 April 28