LinRegVariance (PEL)
This function calculates the linear regression of the values defined by a scope expression and returns the variance associated with the regression line, y = ax + b.
LinRegVariance(
Scope_Expression,
Numeric_Expression_y
[ , Numeric_Expression_x ]
)
Parameters
- Scope_Expression
A valid PerformancePoint Expression Language (PEL) expression that returns a scope.
- Numeric_Expression_y
A valid numeric expression that is typically a PEL expression of cell coordinates that return a number, which represents values for the y-axis.
- Numeric_Expression_x
A valid numeric expression that is typically a PEL expression of cell coordinates that return a number, which represents values for the x-axis.
Return Value
After obtaining the set of points, the LinRegVariance function returns the statistical variance that best describes the fit of the regression line y = ax + b.
Note
LinRegVariance ignores empty cells, or cells that contain text values.
Remarks
Linear regression uses the least-squares method to calculate the equation of a regression line (that is, the best-fit line for a series of points). The regression line has the following equation, where a is the slope and b is the intercept:
y = ax + b
The LinRegVariance function evaluates the specified scope against Numeric_Expression_y to obtain the values for the y-axis. The function then evaluates the specified scope expression against Numeric_Expression_x, if it is specified, to obtain the values for the x-axis.
If Numeric_Expression_x is not specified, the function uses the current context of the cells in the specified scope as the values for the x-axis. Not specifying the x-axis argument is frequently used with the Time dimension.
The PEL compiler cannot generate SQL code for this function.