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Just Some Maths
#1
Just a few things I created back in the late 1990s. First a few constants that you may or may not find useful -

Code: (Select All)
REM ******************************************************************
REM * A number of maths constants that have been pre-calculated in  *
REM * order to save execution time.                                  *
REM ******************************************************************

CONST PI# = 3.14159265358979323846              'PI

CONST PITimes2# = 6.28318530717959              'PI * 2
CONST PITimes3# = 9.42477796076938              'PI * 3
CONST PITimes4# = 12.5663706143592              'PI * 4
CONST PITimes5# = 15.707963267949                'PI * 5
CONST PITimes6# = 18.8495559215388              'PI * 6

CONST PIDividedBy2# = 1.57079632679489661923    'PI / 2
CONST PIDividedBy3# = 1.04719755119659774615    'PI / 3
CONST PIDividedBy4# = 0.78539816339744830962    'PI / 4
CONST PIDividedBy5# = 0.628318530717959          'PI / 5
CONST PIDividedBy6# = 0.52359877559829887308    'PI / 6

CONST PISquared# = 9.86960440108936              'PI * PI
CONST PICubed#  = 31.0062766802998              'PI * PI * PI
CONST SQROfPI#  = 1.77245385090552              'SQR(PI)
CONST ReciprocalOfPI# = 0.31830988618379067154  '1 / PI

CONST TwoDividedByPI#  = 0.63661977236758134308 '2 / PI
CONST ThreeDividedByPI# = 0.954929658551372      '3 / PI
CONST FourDividedByPI#  = 1.27323954473516      '4 / PI
CONST FiveDividedByPI#  = 1.59154943091895      '5 / PI
CONST SixDividedByPI#  = 1.90985931710274      '6 / PI

CONST FourThirdsOfPI#  = 4.18879020478639      '4 / 3 * PI

CONST TheConstantE# = 2.71828182845905

CONST SquareOfE# = 7.38905609893065              'E * E
CONST SQROfE# = 1.64872127070013                'SQR(E)
CONST ReciprocalOfE# = 0.367879441171442        '1 / E

CONST LOG3DividedBy2# = 0.54930614433405484570  'LOG(3) / 2

CONST SQROfPnt5# = 0.70710678118654752440        'SQR(0.5)
CONST SQROf2# = 1.41421356227309504880          'SQR(2)
CONST SQROf3# = 1.73205080756887729353          'SQR(3)
CONST TwoMinusSQROf3# = 0.26794919243112270647  '2 - SQR(3)
CONST TwelthRootOf2# = 1.059463094              '12th root of 2

CONST FeigenbaumConstant# = 4.6692016090

REM ******************************************************************
REM * Distance travelled by light in 1 second, minute, hour, day,    *
REM * year.  Measured in Miles (approximately).                      *
REM ******************************************************************

CONST LightSecondInMiles# = 186271.0
CONST LightMinuteInMiles# = 11176260.0
CONST LightHourInMiles# = 670575600.0
CONST LightDayInMiles# = 16093814400.0
CONST LightYearInMiles# = 5797796637600.0

REM ******************************************************************
REM * Distance travelled by light in 1 second, minute, hour, day,    *
REM * year.  Measured in KiloMeters (approximately).                *
REM ******************************************************************

CONST LightSecondInKiloMeters# = 299774.0
CONST LightMinuteInKiloMeters# = 17986440.0
CONST LightHourInKiloMeters# = 1079186400.0
CONST LightDayInKiloMeters# = 25900473600.0
CONST LightYearInKiloMeters# = 9330645614400.0

Then there is this library of a number maths routines. First the documentation (comments also included in the code) -

Code: (Select All)
REM ******************************************************************
REM * The following routines are entirely devoted to logarithms for  *
REM * bases other than e, which is the base used by QB.  The base    *
REM * used in a particular routine is denoted by the number which    *
REM * suffixes Log in the name of the function, with the exception  *
REM * of LogX where the user supplies the base.                      *
REM ******************************************************************

FUNCTION Log2#(x AS DOUBLE)
FUNCTION Log8#(x AS DOUBLE)
FUNCTION Log10#(x AS DOUBLE)
FUNCTION Log16#(x AS DOUBLE)
FUNCTION LogX#(x AS DOUBLE, LogBase AS DOUBLE)

FUNCTION AntiLog2#(x AS DOUBLE)
FUNCTION AntiLog8#(x AS DOUBLE)
FUNCTION AntiLog10#(x AS DOUBLE)
FUNCTION AntiLog16#(x AS DOUBLE)
FUNCTION AntiLogX#(x AS DOUBLE, LogBase AS DOUBLE)

REM ******************************************************************
REM * Finds the y'th root of x.                                      *
REM ******************************************************************

FUNCTION Root#(x AS DOUBLE, y AS DOUBLE)

REM ******************************************************************
REM * Raise x to the power of y.                                    *
REM ******************************************************************

FUNCTION Power#(x AS DOUBLE, y AS DOUBLE)

REM ******************************************************************
REM * Returns x' = x * (x - 1) * (x - 2) ... * 1.  Non-recursive!    *
REM ******************************************************************

FUNCTION Factorial#(x AS DOUBLE)

REM ******************************************************************
REM * Returns the arithmetic mean (average) and the sample standard  *
REM * deviation of the values held in the array In.                  *
REM ******************************************************************

SUB MeanDeviation(Mean AS DOUBLE, StandardDeviation AS DOUBLE, In#())

REM ******************************************************************
REM * Returns a random number that is constrained to have a          *
REM * greater probability of falling within the centre of upper and  *
REM * lower bounds.                                                  *
REM ******************************************************************

FUNCTION GaussianRnd#(DesiredMean#, DesiredDeviation#)

Finally the code -

Code: (Select All)
OPTION BASE 0

REM ******************************************************************
REM * Pre-calculated constants for use by the logarithmic functions  *
REM ******************************************************************

CONST LOGOf2# = 0.6931471805599453094172321      'LOG(2)
CONST LOGOf8# = 2.07944154167984                  'LOG(8)
CONST LOGOf10# = 2.30258509299405                'LOG(10)
CONST LOGOf16# = 2.77258872223978                'LOG(16)

CONST Log2E# = 1.4426950408889634074              '1/LOG(2)
CONST Log8E# = 0.480898346962988                  '1/LOG(8)
CONST Log10E# = 0.43429448190325182765            '1/LOG(10.0)
CONST Log16E# = 0.360673760222241                '1/LOG(16)

REM ******************************************************************
REM * The following routines are entirely devoted to logarithms for  *
REM * bases other than e, which is the base used by QB.  The base    *
REM * used in a particular routine is denoted by the number which    *
REM * suffixes Log in the name of the function, with the exception  *
REM * of LogX where the user supplies the base.                      *
REM ******************************************************************

FUNCTION Log2#(x AS DOUBLE)
    IF x < 0.0 THEN
        Log2# = 0.0
    ELSE
        Log2# = LOG(x) * Log2E#
    END IF
END FUNCTION

FUNCTION Log8#(x AS DOUBLE)
    IF x < 0.0 THEN
        Log8# = 0.0
    ELSE
        Log8# = Log(x) * Log8E#
    END IF
END FUNCTION

FUNCTION Log10#(x AS DOUBLE)
    IF x < 0.0 THEN
        Log10# = 0.0
    ELSE
        Log10# = Log(x) * Log10E#
    END IF
END FUNCTION

FUNCTION Log16#(x AS DOUBLE)
    IF x < 0.0 THEN
        Log16# = 0.0
    ELSE
        Log16# = Log(x) * Log16E#
    END IF
END FUNCTION

FUNCTION LogX#(x AS DOUBLE, LogBase AS DOUBLE)
    IF ((x < 0.0) OR (LogBase <= 0.0)) THEN
        LogX# = 0.0
    ELSE
        LogX# = Log(x) / Log(LogBase)
    END IF
END FUNCTION

FUNCTION AntiLog2#(x AS DOUBLE)
    AntiLog2# = EXP(LOGOf2# * x)
END FUNCTION

FUNCTION AntiLog8#(x AS DOUBLE)
    AntiLog8# = EXP(LOGOf8# * x)
END FUNCTION

FUNCTION AntiLog10#(x AS DOUBLE)
    AntiLog10# = EXP(LOGOf10# * x)
END FUNCTION

FUNCTION AntiLog16#(x AS DOUBLE)
    AntiLog16# = EXP(LOGOf16# * x)
END FUNCTION

FUNCTION AntiLogX#(x AS DOUBLE, LogBase AS DOUBLE)
    IF ((x <= 0.0) OR (LogBase <= 0.0)) THEN
        AntiLogX# = 0.0
    ELSE
        AntiLogX# = EXP(Log(LogBase) * x)
    END IF
END FUNCTION

REM ******************************************************************
REM * Finds the y'th root of x.                                      *
REM ******************************************************************

FUNCTION Root#(x AS DOUBLE, y AS DOUBLE)
    IF ((x <= 0.0) OR (y = 0.0)) THEN
        Root# = 0.0
    ELSE
        Root# = EXP(LOG(x) / y)
    END IF
END FUNCTION

REM ******************************************************************
REM * Raise x to the power of y.                                    *
REM ******************************************************************

FUNCTION Power#(x AS DOUBLE, y AS DOUBLE)
    IF ((x <= 0.0) OR (y = 0.0)) THEN
        Power# = 0.0
    ELSE
        Power# = EXP(LOG(x) * y)
    END IF
END FUNCTION

REM ******************************************************************
REM * Returns x' = x * (x - 1) * (x - 2) ... * 1.  Non-recursive!    *
REM ******************************************************************

FUNCTION Factorial#(x AS DOUBLE)
    WorkingValue# = 2.0
    ReturnValue# = 1.0
    DO WHILE (WorkingValue# <= x)
        ReturnValue# = ReturnValue# * WorkingValue#
        WorkingValue# = WorkingValue# + 1.0
    LOOP
    Factorial# = ReturnValue#
END FUNCTION

REM ******************************************************************
REM * Returns the arithmetic mean (average) and the sample standard  *
REM * deviation of the values held in the array In.                  *
REM ******************************************************************

SUB MeanDeviation(Mean AS DOUBLE, StandardDeviation AS DOUBLE, In#())
    Sum# = 0.0#
    SumOfSquares# = 0.0#
    StartIndex% = LBOUND(In#)
    NumberOfValues% = UBOUND(In#)
    FOR Index% = StartIndex% TO NumberOfValues%
        Sum# = Sum# + In#(Index%)
        SumOfSquares# = SumOfSquares# + In#(Index%) * In#(Index%)
    NEXT Index%
    Mean = Sum# / NumberOfValues
    StandardDeviation = SQR(SumOfSquares# - Sum# * Sum# / NumberOfValues) / (NumberOfValues - 1.0)
END SUB

REM ******************************************************************
REM * Returns a random number that is constrained to have a          *
REM * greater probability of falling within the centre of upper and  *
REM * lower bounds.                                                  *
REM ******************************************************************

FUNCTION GaussianRnd#(DesiredMean#, DesiredDeviation#)
    RandomSum# = 0#
    FOR x% = 1 TO 12
        RandomSum# = RandomSum# + RND
    NEXT x%
    GausianRnd# = (RandomSum# - 6#) * DesiredDeviation# + DesiredMean#
END FUNCTION

Hope you have a use for these.

TR
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