hg/stx-libbasic: comparison ArithmeticValue.st

equal deleted inserted replaced

-:1e770c64a291
+:55ca5a24162a
 !
 exp
 "return e ^ receiver"
-^ self asFloat exp
+^ self class e raisedTo:self
 !
 floorLog:radix
 "return the logarithm truncated as an integer"
 ^ self asFloat arcCos
 !
 arcCosh
-"return the hyperbolic arccosine of the receiver (in radians)"
+"return the hyperbolic arccosine of the receiver."
 ^ self asFloat arcCosh
 !
 arcSin
 ^ self asFloat arcSin
 !
 arcSinh
-"return the hyperbolic arcsine of the receiver (in radians)"
+"return the hyperbolic arcsine of the receiver."
 ^ self asFloat arcSinh
 !
 arcTan
-"return the arctangens of the receiver (in radians)"
+"return the arctangent of the receiver (as radians)"
 ^ self asFloat arcTan
 !
 arcTanh
-"return the hyperbolic arctangens of the receiver (in radians)"
+"return the hyperbolic arctangent of the receiver."
 ^ self asFloat arcTanh
 !
 cos
 ^ self asFloat cos
 !
 cosh
-"return the hyperbolic cosine of the receiver (interpreted as radians)"
+"return the hyperbolic cosine of the receiver"
-^ self asFloat cosh
+^ (self exp + (self negated exp)) / 2
 !
 sin
 "return the sine of the receiver (interpreted as radians)"
 ^ self asFloat sin
 !
 sinh
-"return the hyperbolic sine of the receiver (interpreted as radians)"
+"return the hyperbolic sine of the receiver"
-^ self asFloat sinh
+^ (self exp - (self negated exp)) / 2
 !
 tan
 "return the tangens of the receiver (interpreted as radians)"
 ^ self asFloat tan
 !
 tanh
-"return the hyperbolic tangens of the receiver (interpreted as radians)"
+"return the hyperbolic tangens of the receiver"
-^ self asFloat tanh
+|exp nexp|
+"/ tanh is:
+"/      sinh(x)
+"/      -------
+"/      cosh(x)
+"/
+"/ which is:
+"/      (exp(x) - exp(-x)) / 2
+"/      ----------------------
+"/      (exp(x) + exp(-x)) / 2
+exp := self exp.
+nexp := self negated exp.
+^ ((exp - nexp) / (exp + nexp)) / 2
 ! !
 !ArithmeticValue methodsFor:'truncation & rounding'!
 ceiling
 ! !
 !ArithmeticValue class methodsFor:'documentation'!
 version
-^ '$Header: /cvs/stx/stx/libbasic/ArithmeticValue.st,v 1.50 2003-06-17 09:11:17 cg Exp $'
+^ '$Header: /cvs/stx/stx/libbasic/ArithmeticValue.st,v 1.51 2003-06-17 11:51:43 cg Exp $'
 ! !
 ArithmeticValue initialize!

changeset 7391	55ca5a24162a
parent 7385	852e84340d2b
child 7393	23344038fa0e