ERFINV

The inverse error function returns the real value whose error function equals the provided input, over the principal real interval.

\mathrm{erf}(\mathrm{erfinv}(y)) = y, \quad -1 \le y \le 1

This wrapper evaluates the real inverse \mathrm{erfinv}(y) using SciPy.

Excel Usage

=ERFINV(y)

• y (float, required): Input value in the real domain of inverse error function (dimensionless).

Returns (float): Inverse error function value for the input.

Example 1: Inverse error function at zero

Inputs:

y
0

Excel formula:

=ERFINV(0)

Expected output:

0

Example 2: Inverse error function at one half

Inputs:

y
0.5

Excel formula:

=ERFINV(0.5)

Expected output:

0.476936

Example 3: Inverse error function at negative one half

Inputs:

y
-0.5

Excel formula:

=ERFINV(-0.5)

Expected output:

-0.476936

Example 4: Inverse error function at one quarter

Inputs:

y
0.25

Excel formula:

=ERFINV(0.25)

Expected output:

0.225312

Python Code

from scipy.special import erfinv as scipy_erfinv

def erfinv(y):
    """
    Compute the inverse error function on its real domain.

    See: https://docs.scipy.org/doc/scipy/reference/generated/scipy.special.erfinv.html

    This example function is provided as-is without any representation of accuracy.

    Args:
        y (float): Input value in the real domain of inverse error function (dimensionless).

    Returns:
        float: Inverse error function value for the input.
    """
    try:
        y = float(y)
        return float(scipy_erfinv(y))
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

y *

Input value in the real domain of inverse error function (dimensionless).