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# error Fn C inv

Evaluates the inverse of the complementary error function.
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Private project under development, to help contact the author:

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## ErrorFnC Inv

 doubleerrorFnC_inv( double y )
The inverse of the complementary error function is defined as the function which satisfies:

where is the complementary error function. Some special values are:

The graph of this function is shown below.
There is an error with your graph parameters for errorFnC_inv with options y=0:2

Error Message:Function errorFnC_inv failed. Ensure that: --2147483648.0000000000

The following property also holds:

where is the inverse of the error function. Based on this last formula, you may notice how the output of the example code below is linked to the example output in the errorFn_inv module.

## References:

Mathworld, http://mathworld.wolfram.com/InverseErfc.html

### Example 1

#include <codecogs/maths/special/errorfnc_inv.h>
#include <stdio.h>

int main(  )
{
// display the value of the function at important points
printf("x = 0     y = %.15lf\n",   Maths::Special::errorFnC_inv(0.0));
printf("x = 1     y = %.15lf\n",   Maths::Special::errorFnC_inv(1.0));
printf("x = 2     y = %.15lf\n\n", Maths::Special::errorFnC_inv(2.0));

// display several values of the function
// at equally spaced abscissas with a step of 0.1
for (double x = 1.1; x < 1.99; x += 0.1)
printf("x = %.1lf   y = %.15lf\n",
x, Maths::Special::errorFnC_inv(x));

return 0;
}

### Output

x = 0     y = 1.#INF00000000000
x = 1     y = 0.000000000000000
x = 2     y = -1.#INF00000000000

x = 1.1   y = -0.088855990494258
x = 1.2   y = -0.179143454621292
x = 1.3   y = -0.272462714726755
x = 1.4   y = -0.370807158593558
x = 1.5   y = -0.476936276204471
x = 1.6   y = -0.595116081449996
x = 1.7   y = -0.732869077959218
x = 1.8   y = -0.906193802436824
x = 1.9   y = -1.163087153676677

### Parameters

 y the value at which to evaluate the function ()

### Returns

The inverse of the complementary error function.

### Authors

Lucian Bentea (September 2006)
##### Source Code

This module is private, for owner's use only.

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