根据“样条”多项式旋转数据有问题吗？

问题描述

这是问题所在的代码：

angles = -atan(deriv)

angles = angles*(180/pi)



#shift coordinates onto their polynomials

d[1:mtp,3] = d[1:mtp,3] + poly[,2]



#rotated storage matrix

rrr = as.data.frame(matrix(data = NA,ncol = 2,nrow = 9000))



#for each moment,take in old coordinates and export newly rotated

for(i in 1:mtp){

rotm = matrix(data = c(c(cos(angles[i]),sin(angles[i])),c(-sin(angles[i]),cos(angles[i]))),ncol=2,nrow = 2)

rotate.1 = d[i,2:3] - poly[i,]

rotate.2 = rotm %*% t(rotate.1)

rotate.3 = rotate.2 + poly[i,]

rrr[i,] = rotate.3

}



#overwrite coordinates with rotations

d[1:mtp,2:3] = rrr

"deriv" 是一个数值向量，包含沿多项式样条 "poly" 的每个点的导数，列 1:2 x 和 y。因此，“angles”包含计算出的每个点旋转的角度。 “d”是初始数据矩阵，列 2:3 是 x 和 y。

Data to be translated and rotated

"Spline" polynomial along which data will be translated and rotated

Angles along polynomial used during rotation (derived from derivative)

Data + Spline (translated)

Translated and (incorrectly) rotated data

解决方法

已解决：R 三角函数使用弧度，因此脚本不必要地转换为度数并导致过度校正，比例为 180/pi。