LINEST_R2  chart function
LINEST_R2() returns the
aggregated
Syntax:
LINEST_R2([{SetExpression}] [DISTINCT] [TOTAL [<fld{, fld}>]] y_value, x_value[, y0_const[, x0_const]])
Return data type: numeric
Arguments:
Argument  Description 

y_value  The expression or field containing the range of 
x_value  The expression or field containing the range of 

An optional
value Note: Unless both

SetExpression  By default, the aggregation function will aggregate over the set of possible records defined by the selection. An alternative set of records can be defined by a set analysis expression. 
DISTINCT  If the word DISTINCT occurs before the function arguments, duplicates resulting from the evaluation of the function arguments are disregarded. 
TOTAL 
If the word TOTAL occurs before the function arguments, the calculation is made over all possible values given the current selections, and not just those that pertain to the current dimensional value, that is, it disregards the chart dimensions. By using TOTAL [<fld {.fld}>], where the TOTAL qualifier is followed by a list of one or more field names as a subset of the chart dimension variables, you create a subset of the total possible values. 
Limitations:
The expression must not contain aggregation functions, unless these inner aggregations contain the TOTAL qualifier. For more advanced nested aggregations, use the advanced aggregation function Aggr, in combination with calculated dimensions.
Text values,