Warning: Variable 'a' cannot be saved to a MAT-file whose version is older than 7.3.

matlab错误提示：


Warning: Variable 'a' cannot be saved to a MAT-file whose version
is older than 7.3.
To save this variable, use the -v7.3 switch.

Skipping...

解决办法：


打开matlab，file/preferences，general选项卡-MAT-Files,选择第一个。