erf() - The Gauss error function

[BSpinoza]

This calculates the Gauss error function and the complementary Gauss error function:

Code: (Select All)

'The Gauss error function and the complementary Gauss error function

DIM AS _FLOAT a, n

a = 0.05

PRINT erf##(a)

PRINT erfc##(a)



FUNCTION erf## (value AS DOUBLE) 'the Gauss error function

    t## = 1 / (1 + 0.5 * ABS(value))

    tau## = t## * EXP(-value ^ 2 - 1.26551223 + 1.00002368 * t## + 0.37409196 * t## ^ 2 + 0.09678418 * t## ^ 3 - 0.18628806 * t## ^ 4 + 0.27886807 * t## ^ 5 - 1.13520398 * t## ^ 6 + 1.48851587 * t## ^ 7 - 0.82215223 * t## ^ 8 + 0.17087277 * t## ^ 9)

    IF value >= 0 THEN

        erf## = 1 - tau##

    ELSEIF value < 0 THEN

        erf## = tau## - 1

    END IF

END FUNCTION





FUNCTION erfc## (value AS DOUBLE) 'the complementary Gauss error function

    erfc## = 1 - erf##(value)

END FUNCTION

  

This are standard functions of many math libraries of other programming languages.