NAG CL Interface
s15arc (erfc_​real_​vector)

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1 Purpose

s15arc returns an array of values of the complementary error function, erfc(x).

2 Specification

#include <nag.h>
void  s15arc (Integer n, const double x[], double f[], NagError *fail)
The function may be called by the names: s15arc, nag_specfun_erfc_real_vector or nag_erfc_vector.

3 Description

s15arc calculates approximate values for the complement of the error function
erfc(x) = 2π x e-t2 dt = 1-erf(x) ,  
for an array of arguments xi, for i=1,2,,n.
See s15adc for details on the algorithm used.

4 References

None.

5 Arguments

1: n Integer Input
On entry: n, the number of points.
Constraint: n0.
2: x[n] const double Input
On entry: the argument xi of the function, for i=1,2,,n.
3: f[n] double Output
On exit: erfc(xi), the function values.
4: fail NagError * Input/Output
The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).

6 Error Indicators and Warnings

NE_ALLOC_FAIL
Dynamic memory allocation failed.
See Section 3.1.2 in the Introduction to the NAG Library CL Interface for further information.
NE_BAD_PARAM
On entry, argument value had an illegal value.
NE_INT
On entry, n=value.
Constraint: n0.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 7.5 in the Introduction to the NAG Library CL Interface for further information.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library CL Interface for further information.

7 Accuracy

Not applicable.

8 Parallelism and Performance

Background information to multithreading can be found in the Multithreading documentation.
s15arc is not threaded in any implementation.

9 Further Comments

None.

10 Example

This example reads values of x from a file, evaluates the function at each value of xi and prints the results.

10.1 Program Text

Program Text (s15arce.c)

10.2 Program Data

Program Data (s15arce.d)

10.3 Program Results

Program Results (s15arce.r)