'----------------------------------------------------------------------------------------
'    Name:  EXP_REAL.TIG
'    Type:  TIGER-BASIC(tm) Source Code
' Purpose:  Creating the EXP function for a floating point base and
'           exponent, based on the term:  a^x = e^(x*ln(a))
'
'  (C) - Copyright Wilke Technology, P.O.Box 1727, D-52018 Aachen, Germany
'----------------------------------------------------------------------------------------
'
' Thank you for using BASIC Tigers in your products. If you have questions, ideas
' or special needs, please contact your next distributor or the Tiger support team
' and visit our web site:
'
'	Wilke Technology GmbH
'	The Tiger Support Team
'	P.O.Box 1727,       D-52018 Aachen, Germany
'	Krefelder Str. 147, D-52070 Aachen, Germany
'
'	email: support@wilke-technology.com  (english)
'	email: support@wilke.de              (german)
'	Phone: +49 (241) 918 900    Mo to Fr, 7:00 to 16:00 (GMT)
'	Fax:   +49 (241) 918 9068
'
' New information, new drivers and free downloads see:
'
'	www.wilke-technology.com	     (english)
'	www.wilke.de                         (german)
'
' Sincerely,
'
'	Your Tiger Support Team
'
'----------------------------------------------------------------------------------------
'
' The exponential functions of Tiger-BASIC are only suited for fixed point values, e.g.
' 16^4, 2^20 etc. If you need to calculate a product where base and exponent consist of
' floating point values, you can use the subroutine EXP_REAL:
'
'    CALL EXP_REAL (f, b, e)
'
' where
'    -  f is the function value which gets calculated by the subroutine,
'    -  b is the value for the base and
'    -  e is the value for the exponent.
'
'----------------------------------------------------------------------------------------
TASK MAIN                               ' begin task MAIN

  REAL k, T, x, fT			' declare REAL variables

  INSTALL_DEVICE #1, "LCD1.TDD"		' install LCD driver

  USING "NF<0><1> <9>V0.0.0.0.0.0.0.0,0.0.0.0.0.0.0.0"	' string for formatted output

  k = 26.4				' value for base
  T = 2.65				' value for exponent
  CALL EXP_REAL (fT, k, T)		' call calculation of fT = k^T
  PRINT_USING #1, "<1> k:"; k		' display base
  PRINT_USING #1, " T:"; T		' display exponent
  PRINT_USING #1, "fT:"; fT		' display product
END					' ende of task MAIN


'----------------------------------------------------------------------------------------
' Subroutine for floating point exponential function using a^x = e^(x*ln(a)) 
'----------------------------------------------------------------------------------------
SUB EXP_REAL (VAR REAL f; REAL b, e)	' begin subroutine EXP_REAL
  REAL x				' declare REAL variable for new exponent
  x = e * LN(b)				' determine new exponent
  f = EXPE(x)				' result = exponent to base e
END					' end of subroutine EXP_REAL