# WorksheetFunction.LogEst (Excel)

In regression analysis, calculates an exponential curve that fits your data, and returns an array of values that describes the curve. Because this function returns an array of values, it must be entered as an array formula.

The equation for the curve is y = b*m^x or y = (b*(m1^x1)*(m2^x2)*_) (if there are multiple x-values), where the dependent y-value is a function of the independent x-values. The m-values are bases corresponding to each exponent x-value, and b is a constant value. Note that y, x, and m can be vectors. The array that LogEst returns is {mn,mn-1,...,m1,b}. If the array known_y's is in a single column, each column of known_x's is interpreted as a separate variable. If the array known_y's is in a single row, each row of known_x's is interpreted as a separate variable. The array known_x's can include one or more sets of variables. If only one variable is used, known_y's and known_x's can be ranges of any shape, as long as they have equal dimensions. If more than one variable is used, known_y's must be a range of cells with a height of one row or a width of one column (which is also known as a vector). If known_x's is omitted, it is assumed to be the array {1,2,3,...} that is the same size as known_y's.

**LogEst** (Arg1, Arg2, ..., Arg4)

```
Dim arrLogEst() As Variant
arrLogEst() = WorksheetFunction.LogEst(Arg1:=)
```

## Arguments

Arg1, Arg2, ..., Arg4Arg1 - Known_y's - the set of y-values that you already know in the relationship y = b*m^x

Arg2 - Known_x's - an optional set of x-values that you may already know in the relationship y = b*m^x

Arg3 - Const - a logical value specifying whether to force the constant b to equal 1

Arg4 - Stats - a logical value specifying whether to return additional regression statistics