Correction to: Stretching and shearing contamination analysis for Liutex and other vortex identification methods

Correction to:Adv Aerodyn 3,8(2021)https://doi.org/10.1186/s42774-020-00060-9 After publication of this article[1],it is noticed letter‘a’is missing from the below sentence in section 6.2‘Adding stretching components’:The subscript“”means“adding”the stretching components.The correct sentence should be。