Column pair j is sin(2 pi j t / m), cos(2 pi j t / m) for j = 1..k. The book calls these trigonometric seasonality.
Examples
morie_fourfeat(n = 24, period = 12, k = 2)
#> $rows
#> [,1] [,2] [,3] [,4]
#> [1,] 0.000000e+00 1.000000e+00 0.000000e+00 1.0
#> [2,] 5.000000e-01 8.660254e-01 8.660254e-01 0.5
#> [3,] 8.660254e-01 5.000000e-01 8.660254e-01 -0.5
#> [4,] 1.000000e+00 6.123234e-17 1.224647e-16 -1.0
#> [5,] 8.660254e-01 -5.000000e-01 -8.660254e-01 -0.5
#> [6,] 5.000000e-01 -8.660254e-01 -8.660254e-01 0.5
#> [7,] 1.224647e-16 -1.000000e+00 -2.449294e-16 1.0
#> [8,] -5.000000e-01 -8.660254e-01 8.660254e-01 0.5
#> [9,] -8.660254e-01 -5.000000e-01 8.660254e-01 -0.5
#> [10,] -1.000000e+00 -1.836970e-16 3.673940e-16 -1.0
#> [11,] -8.660254e-01 5.000000e-01 -8.660254e-01 -0.5
#> [12,] -5.000000e-01 8.660254e-01 -8.660254e-01 0.5
#> [13,] -2.449294e-16 1.000000e+00 -4.898587e-16 1.0
#> [14,] 5.000000e-01 8.660254e-01 8.660254e-01 0.5
#> [15,] 8.660254e-01 5.000000e-01 8.660254e-01 -0.5
#> [16,] 1.000000e+00 1.194340e-15 2.388680e-15 -1.0
#> [17,] 8.660254e-01 -5.000000e-01 -8.660254e-01 -0.5
#> [18,] 5.000000e-01 -8.660254e-01 -8.660254e-01 0.5
#> [19,] 3.673940e-16 -1.000000e+00 -7.347881e-16 1.0
#> [20,] -5.000000e-01 -8.660254e-01 8.660254e-01 0.5
#> [21,] -8.660254e-01 -5.000000e-01 8.660254e-01 -0.5
#> [22,] -1.000000e+00 -4.286264e-16 8.572528e-16 -1.0
#> [23,] -8.660254e-01 5.000000e-01 -8.660254e-01 -0.5
#> [24,] -5.000000e-01 8.660254e-01 -8.660254e-01 0.5
#>
#> $nrows
#> [1] 24
#>
#> $ncols
#> [1] 4
#>
#> $k
#> [1] 2
#>
#> $period
#> [1] 12
#>
#> $mean
#> [1] -2.091268e-17
#>
#> $sumsq
#> [1] 48
#>
