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exp(3F)

erf(3F)

NAME

erf, erfc − error function and complementary error function

SYNOPSIS

double precision function erf (x)
double precision x;

double precision function erfc (x)
double precision x;

DESCRIPTION

erf returns the error function of x, defined as 2 / sqrt(Pi) ∗ integral[0, x] exp(-(t∗∗2)) dt

erfc, which returns 1.0 − erf(x), is provided because of the extreme loss of relative accuracy if erf(x) is called for large x and the result subtracted from 1.0 (e.g., for x = 5, 12 places are lost). 

SEE ALSO

exp(3F). 

NOTES

When compiling source with the -Qocs option, an explicit underscore needs to be added to the end of the routine names. 

CX/UX Hf77 Fortran Reference Manual

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