Documentation/How Tos/Calc: FORECAST function
From Apache OpenOffice Wiki
FORECAST
Fits a straight line to data using linear regression and returns a point on that line.
Syntax:
FORECAST(new_xvalue; yvalues; xvalues)
- yvalues and xvalues are single row or column ranges specifying points in a set of data. yvalues and xvalues must be the same size.
- FORECAST fits a straight line through these data points, using the linear regression method.
- FORECAST returns the y value on the straight line found, corresponding to the x value in new_xvalue. It is equivalent to TREND(yvalues; xvalues; new_xvalue).
- Advanced topic:
- The parameters xvalues and yvalues are always evaluated as array formulas. Note that TREND does not evaluate its parameters as array formulas.
Example:
FORECAST(6; B2:B6; A2:A6)
- where the x values in A2:A6 are 1, 2, 3, 4, 5 and the y values in B2:B6 are 2, 4, 7, 8, 11 returns 13.
TREND(B2:B6; A2:A6; 6)
- with the same x values and y values, also returns 13.