模式识别相似性测度（欧氏距离、马氏距离等）

比眉伴天荒 2023-07-09 02:29 17阅读 0赞

## **定义** ##

测度就是用于测量两个模式之间距离的方法

![20200303140328566.png][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjg1MjY1_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjg1MjY1_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjg1MjY1_size_16_color_FFFFFF_t_70 2][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjg1MjY1_size_16_color_FFFFFF_t_70 3][]

# #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjg1MjY1_size_16_color_FFFFFF_t_70 4][]

由此可知，欧氏距离和马氏距离的差别在于欧氏距离认为各个变量之间的距离的单位是相同的，而马氏距离各变量之间的单位是有大小的，这个大小是有协方差决定的

## 举个例子： ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjg1MjY1_size_16_color_FFFFFF_t_70 5][]

由此可以看出，很多时候马氏距离比欧氏距离在应用的过程中更合理一些

[20200303140328566.png]: https://img-blog.csdnimg.cn/20200303140328566.png
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