Specifies how the trendline for a series data is calculated.
Calculates the least squares fit for the exponential curve y = a * b^x.
Calculates the least squares fit for the line y = m * x + b.
Calculates a least squares fit for the logarithmic curve y = a * ln(x) + b, where ln is the natural logarithm.
Uses a sequence of averages calculated across each set of N consecutive values, where N is the number specified for the Trendline.Period.
Calculates a least square fit using a polynomial curve of order equal to the number specified by the Trendline.Order property. The equation is in the form y = b + (c1 * x) + (c2 * x^2) + ... + (cN * x^N) where N is the trendline order.
Calculates a least square fit for a power curve in the form y = a * x^b.