The quadratic component of trend is used to test whether the

Trend analysis is computed as a set of orthogonal comparisons using a particular set of coefficients. Coefficients for the linear, quadratic, and cubic components of trend are given below:

2 means Lin -1 1 3 means Lin -1 0 1 Quad 1 -2 1 4 means Lin -3 -1 1 3 Quad 1 -1 -1 1 Cubic -1 3 -3 1 5 means Lin -2 -1 0 1 2 Quad 2 -1 -2 -1 2 Cubic -1 2 0 -2 1 6 means Lin -5 -3 -1 1 3 5 Quad 5 -1 -4 -4 -1 5 Cubic -5 7 4 -4 -7 5 7 means Lin -3 -2 -1 0 1 2 3 Quad 5 0 -3 -4 -3 0 5 Cubic -1 1 1 0 -1 -1 1 8 means Lin -7 -5 -3 -1 1 3 5 7 Quad 7 1 -3 -5 -5 -3 1 7 Cubic -7 5 7 3 -3 -7 -5 7 9 means Lin -4 -3 -2 -1 0 1 2 3 4 Quad 28 7 -8 -17 -20 -17 -8 7 28 Cubic -14 7 13 9 0 -9 -13 -7 14 10 means Lin -9 -7 -5 -3 -1 1 3 5 7 9 Quad 6 2 -1 -3 -4 -4 -3 -1 2 6 Cubic -42 14 35 31 12 -12 -31 -35 -14 42