设已知点A(p,q),任意直线ax + by + c = 0 (a,b不同时为0),A关于该直线的对称点为A'(p',q')a = 0时b = 0,直线与一个坐标轴平行,应当很容易做,这里省略.ax + by + c = 0y = -ax/b - c/b斜率k = -a/bAA'⊥直线,AA'斜率k...

p' = p - 2a(ap + bq + c)/(a² + b²)

q' = [(a² - b²)q - ab(ap + c)]/(a² + b²)