Documentation/Calc Functions/FORECAST

Function name:
FORECAST

Category:
Statistical Analysis

Summary:
Extrapolates future values based on existing x and y values.

Syntax:
FORECAST(Value; DataY; DataX)

Returns:
Returns a real number which is the predicted value of y using linear regression for the given Value and the 2 data sets, DataY and DataX.

Arguments:
Value is a real number or a reference to the cell containing that number which is the x value, for which the y value on the linear regression is to be returned.

DataY is the array or a reference to the range of known y values.

DataX is the array or a reference to the range of known x values.


 * If DataX has variance of 0 then the function returns a division(#DIV/0!) error.
 * If dimensions of DataX and DataY are not same then the function returns an error value.
 * If either DataX or DataY is an empty array then the function returns an error value and if either of them is a reference to a range of empty cells then the function returns a #VALUE! error.

Additional details:

 * The equation for FORECAST is

y = &alpha; + &beta;x,

where &alpha; = ӯ - &beta;x̄ and &beta; is given as:

Here x̄ and ӯ are mean values for DataX and DataY, respectively.
 * FORECAST and FORECAST.LINEAR performs the same operation.

Related LibreOffice functions:
FORECAST.ETS.ADD

FORECAST.ETS.MULT

FORECAST.ETS.PI.ADD

FORECAST.ETS.PI.MULT

FORECAST.ETS.SEASONALITY

FORECAST.ETS.STAT.ADD

FORECAST.ETS.STAT.MULT

FORECAST.LINEAR

ODF standard:
Section 6.18.28, part 2

Equivalent Excel functions:
FORECAST