BPF算法（回溯粒子滤波），还包括判断粒子是否有效的子函数，以及其中用到的判断两条直线是否相交的函数（用来判断轨迹是否与墙壁相交）。- three particle filter algorithms(SIR,ASIR and BPF) for indoor pedestrian navigation.Also include a function for particle validation detection and a function to check if two lines i

粒子滤波典型程序，包括多种重采样方法，可用于导航制导、目标跟踪和图像处理。-Particle filter typical procedure, including resampling method can be used for navigation guidance, target tracking and image processing.