三维坐标转换
如果坐标(x,y,z)->(y,-z,-x)可以使用坐标系:
import mathdef mat_vec_mult(matrix, vector):"""将 3x3 矩阵与 3x1 向量相乘。参数:matrix: 3x3 的旋转矩阵vector: 3x1 的向量返回:3x1 的结果向量"""result = [0, 0, 0]for i in range(3):result[i] = sum(matrix[i][j] * vector[j] for j in range(3))return resultdef rotation_matrix_intrinsic_xyz(alpha, beta, gamma, degrees=True):"""计算内旋顺序(绕 x、y、z 轴)下的旋转矩阵。参数:alpha: 绕 x 轴的旋转角度beta: 绕 y 轴的旋转角度gamma: 绕 z 轴的旋转角度degrees: 如果为 True,则输入角度为度;否则为弧度返回:3x3 的旋转矩阵,作为嵌套列表"""if degrees:alpha = math.radians(alpha)beta = math.radians(beta)gamma = math.radians(gamma)# 绕 x 轴的旋转矩阵Rx = [[1, 0, 0],[0, math.cos(alpha), -math.sin(alpha)],[0, math.sin(alpha), math.cos(alpha)]]# 绕 y 轴的旋转矩阵Ry = [[ math.cos(beta), 0, math.sin(beta)],[0, 1, 0],[-math.sin(beta), 0, math.cos(beta)]]# 绕 z 轴的旋转矩阵Rz = [[math.cos(gamma), -math.sin(gamma), 0],[math.sin(gamma), math.cos(gamma), 0],[0, 0, 1]]# 矩阵乘法:R = Rx * Ry * Rzdef mat_mult(A, B):result = [[0]*3 for _ in range(3)]for i in range(3):for j in range(3):result[i][j] = sum(A[i][k] * B[k][j] for k in range(3))return result# R = mat_mult(Rx, mat_mult(Ry, Rz))R=mat_mult(Rz, mat_mult(Ry, Rx))return R# 示例:绕 x 轴旋转 30 度,绕 y 轴旋转 45 度,绕 z 轴旋转 60 度
# alpha = -90 # 绕 x 轴的角度
# beta = 180 # 绕 y 轴的角度
# gamma = 45 # 绕 z 轴的角度alpha = -90 # 绕 x 轴的角度
beta = 0 # 绕 y 轴的角度
gamma = 90 # 绕 z 轴的角度rotation_matrix = rotation_matrix_intrinsic_xyz(alpha, beta, gamma)print("旋转矩阵:")
for row in rotation_matrix:print(row)a=[0,0,1]
# 应用旋转矩阵+
b = mat_vec_mult(rotation_matrix, a)print("旋转矩阵:",b)
这里,用内旋方法(每次都绕自己变化的轴转),R=Rz*Ry*Rx先绕x轴转,再绕y轴转,最后绕z轴转,可得到结果。
也可以用外旋的方法,绕x轴转,再绕y轴转,最后绕z轴转R=Rx*Ry*Rz,绕原来的坐标轴:
import mathdef mat_vec_mult(matrix, vector):"""将 3x3 矩阵与 3x1 向量相乘。参数:matrix: 3x3 的旋转矩阵vector: 3x1 的向量返回:3x1 的结果向量"""result = [0, 0, 0]for i in range(3):result[i] = sum(matrix[i][j] * vector[j] for j in range(3))return resultdef rotation_matrix_intrinsic_xyz(alpha, beta, gamma, degrees=True):"""计算内旋顺序(绕 x、y、z 轴)下的旋转矩阵。参数:alpha: 绕 x 轴的旋转角度beta: 绕 y 轴的旋转角度gamma: 绕 z 轴的旋转角度degrees: 如果为 True,则输入角度为度;否则为弧度返回:3x3 的旋转矩阵,作为嵌套列表"""if degrees:alpha = math.radians(alpha)beta = math.radians(beta)gamma = math.radians(gamma)# 绕 x 轴的旋转矩阵Rx = [[1, 0, 0],[0, math.cos(alpha), -math.sin(alpha)],[0, math.sin(alpha), math.cos(alpha)]]# 绕 y 轴的旋转矩阵Ry = [[ math.cos(beta), 0, math.sin(beta)],[0, 1, 0],[-math.sin(beta), 0, math.cos(beta)]]# 绕 z 轴的旋转矩阵Rz = [[math.cos(gamma), -math.sin(gamma), 0],[math.sin(gamma), math.cos(gamma), 0],[0, 0, 1]]# 矩阵乘法:R = Rx * Ry * Rzdef mat_mult(A, B):result = [[0]*3 for _ in range(3)]for i in range(3):for j in range(3):result[i][j] = sum(A[i][k] * B[k][j] for k in range(3))return resultR = mat_mult(Rx, mat_mult(Ry, Rz)) #外旋# R=mat_mult(Rz, mat_mult(Ry, Rx)) #内旋return R# 示例:绕 x 轴旋转 30 度,绕 y 轴旋转 45 度,绕 z 轴旋转 60 度
# alpha = -90 # 绕 x 轴的角度
# beta = 180 # 绕 y 轴的角度
# gamma = 45 # 绕 z 轴的角度alpha = -90 # 绕 x 轴的角度
beta = -90 # 绕 y 轴的角度
gamma = 0 # 绕 z 轴的角度rotation_matrix = rotation_matrix_intrinsic_xyz(alpha, beta, gamma)print("旋转矩阵:")
for row in rotation_matrix:print(row)a=[1,0,0]
# 应用旋转矩阵+
b = mat_vec_mult(rotation_matrix, a)print("旋转矩阵:",b)