In Google Sheets, the FISHER function is used to calculate the Fisher transformation of a given value.

The Fisher transformation is commonly used in statistics to stabilize the variance of data and to improve the normality of the distribution.

The syntax of the FISHER function is as follows:

FISHER(value)

The value parameter represents the numeric value for which you want to calculate the Fisher transformation.

The FISHER function returns the transformed value, which is the natural logarithm (base e) of the ratio of (1 + value) to (1 - value). Mathematically, it can be expressed as:

FISHER(value) = LN((1 + value) / (1 - value))

Note that the input value for the FISHER function must be between -1 and 1 (exclusive). If the value is outside this range, the function will return an error.

The Fisher transformation is commonly used in statistical analyses, particularly when working with correlations or when the assumption of normality is required for further analysis.