R: How to or should I drop an insignificant orthogonal polynomial basis in a linear model?
问题 I have soil moisture data with x-, y- and z-coordinates like this: gue <- structure(list(x = c(311939.1507, 311935.4607, 311924.7316, 311959.553, 311973.5368, 311953.3743, 311957.9409, 311948.3151, 311946.7169, 311997.0803, 312017.5236, 312006.0245, 312001.5179, 311992.7044, 311977.3076, 311960.4159, 311970.6047, 311957.2564, 311866.4246, 311870.8714, 311861.4461, 311928.7096, 311929.6291, 311929.4233, 311891.2915, 311890.3429, 311900.8905, 311864.4995, 311870.8143, 311866.9257, 312002.571,