# LinRegR2 (MDX)

Calculates the linear regression of a set and returns the coefficient of determination, R^{2}.

## Syntax

```
LinRegR2(Set_Expression, Numeric_Expression_y [ ,Numeric_Expression_x ] )
```

## Arguments

*Set_Expression*

A valid Multidimensional Expressions (MDX) expression that returns a set.

*Numeric_Expression_y*

A valid numeric expression that is typically a Multidimensional Expressions (MDX) expression of cell coordinates that return a number that represents values for the y-axis.

*Numeric_Expression_x*

A valid numeric expression that is typically a Multidimensional Expressions (MDX) expression of cell coordinates that return a number that represents values for the x-axis.

## Remarks

Linear regression, that uses the least-squares method, calculates 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 **LinRegR2** function evaluates the specified setagainst the first numeric expressionto obtain the values for the y-axis. The function then evaluates the specified set against the second numeric expression, if specified, to obtain the values for the x-axis. If the second numeric expressionis not specified, the function uses the current context of the cells in the specified set as the values for the x-axis. Not specifying the x-axisargument is frequently used with the Time dimension.

After obtaining the set of points, the **LinRegR2** function returns the statistical R^{2} that describes the fit of the linear equation to the points.

Note

The **LinRegR2** function ignores empty cells or cells that contain text or logical values. However, the function includes cells with values of zero.

## Example

The following example returns the statistical R^{2} that describes the goodness of fit of the linear regression equation to the points for the unit sales and the store sales measures.

```
LinRegR2(LastPeriods(10), [Measures].[Unit Sales],[Measures].[Store Sales])
```