This sample shows how to add a trendline in wijscatterchart.
It also shows how to use fitType, order and sampleCount options to customize the trendline.
fitType: It specifies the type of the trendline. There are 11 kinds. You can choose it from the list box above.
sampleCount: It specifies the sample count for function calculation. It works when the fitType is polynom, power, exponent, logarithmic and fourier. It decides the count of the data items for function calculation. It should be set to some integer value greater than 0.
order: It defines the number of terms in polynom equation. It should be set to some integer value greater than 1. It works when the fitType is polynom, power, exponent, logarithmic and fourier. When the fitType is power, exponent and logarithmic, its value is fixed to 2 no matter what it is set to.