本人是学心理学的，然后用眼动仪做实验，眼动仪记录了不同时间眼睛的横纵坐标位置，采样频率350HZ,然后想用butterworth低通过滤器过滤一下，把数据给做一下平滑，请问如何设计butterworth过滤器？参数如何设定？眼动仪保存的文件是记事本格式，第一列是时间，第二列是横坐标，第三列是纵坐标，如何用设计好的过滤器来过滤这些数据？记事本文件需要转换成别的格式才能过滤吗？
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