Documentation/Calc Functions/GROWTH

Function name:
GROWTH

Category:
Array

Summary:
Uses supplied data to predict future growth based on an exponential regression. The function can be used in many fields where growth occurs exponentially, for example population growth, epidemiology, finance, and economics.

GROWTH finds the exponential curve that is the best fit to the supplied data set and returns data points that lie on the general curve $$y(x)=bm^x$$, where $$b$$ is the value of $$y(0)$$ and $$m$$ is a constant.

Syntax:
GROWTH(Data Y [; [ Data X ] [; [ New Data X ] [; Function Type ] ] ])

Returns:
Returns an array of positive decimal numbers that comprise the predicted y-values calculated using an exponential regression. The dimensions of the returned array depend on the nature of the arguments.

Arguments:
Data Y contains the set of known y-values to be used to determine the regression equation. This argument can take the form of an explicit cell range (such as A1:C100), the name of a named range, the name of a database range, or an inline constant array.

Data X contains the set of known x-values to be used to determine the regression equation. This argument can take the form of an explicit cell range (such as D1:D100), the name of a named range, the name of a database range, or an inline constant array. If omitted, it is set to the array {1, 2, 3, …, k}, where k is the number of values in Data Y.

New Data X contains the set of x-values for which predicted y-values are to be calculated. This argument can take the form of an explicit cell range (such as E1:E10), the name of a named range, the name of a database range, or an inline constant array. If omitted, New Data X is set to Data X.

Function Type is a Boolean expression, or a reference to a cell containing a Boolean expression, that determines whether the constant $$b$$ of the exponential curve is set to 1. If Function Type is FALSE or zero, $$b$$ is set to 1. If Function Type is TRUE, non-zero, or omitted, $$b$$ is calculated from the known data.


 * If any entry in Data Y, Data X, or New Data X is non-numeric, then GROWTH reports an invalid argument error (Err:502).
 * If any number in Data Y is negative or zero, then GROWTH reports an invalid argument error (Err:502).
 * If Data Y is neither a single-column vector nor a single-row vector, then Data Y and Data X must have the same dimensions. If this condition is not met, then GROWTH reports an invalid argument error (Err:502).
 * If Data Y is a single-column vector, then Data Y and Data X must have the same number of rows. If this condition is not met, then GROWTH reports an invalid argument error (Err:502).
 * If Data Y is a single-row vector, then Data Y and Data X must have the same number of columns. If this condition is not met, then GROWTH reports an invalid argument error (Err:502).

Details specific to GROWTH function

 * Although the term "growth" is used throughout this wiki page, depending on the input data it is possible for the GROWTH function to return values that represent decay rather than growth.


 * More background information can be found at Wikipedia's Exponential growth page and in the sources that it references.

Related LibreOffice functions:
TREND

ODF standard:
Section 6.18.35, part 2

Equivalent Excel functions:
GROWTH