ERFCE
This function evaluates the exponentially scaled complementary error function.
Function Return Value
ERFCE — Function value. (Output)
Required Arguments
X — Argument for which the function value is desired. (Input)
FORTRAN 90 Interface
Generic: ERFCE (X)
Specific: The specific interface names are S_ERFCE and D_ERFCE.
FORTRAN 77 Interface
Single: ERFCE (X)
Double: The double precision function name is DERFCE.
Description
The function ERFCE(X) computes
where erfc(
x) is the complementary error function. See
ERFC for its definition.
To prevent the answer from underflowing, x must be greater than
where b = AMACH(2) is the largest representable floating‑point number.
Comments
Informational Error
Type | Code | Description |
|---|
2 | 1 | The function underflows because X is too large. |
Example
In this example, ERFCE(1.0) = e1.0 erfc(1.0) is computed and printed.
USE ERFCE_INT
USE UMACH_INT
IMPLICIT NONE
! Declare variables
INTEGER NOUT
REAL VALUE, X
! Compute
X = 1.0
VALUE = ERFCE(X)
! Print the results
CALL UMACH (2, NOUT)
WRITE (NOUT,99999) X, VALUE
99999 FORMAT (' ERFCE(', F6.3, ') = ', F6.3)
END
Output
ERFCE( 1.000) = 0.428
