# Rank-revealing QR/SVD Decompositions

**URL:** <https://discourse.julialang.org/t/rank-revealing-qr-svd-decompositions/21155>\
**Category:** Numerics\
**Created:** [February 24, 2019, 8:27pm UTC](https://discourse.julialang.org/t/rank-revealing-qr-svd-decompositions/21155 "2019-02-24T20:27:23Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Hans\_W\_Borchers](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/hans_w_borchers/32/8481_2.png) [@Hans\_W\_Borchers](https://discourse.julialang.org/u/Hans_W_Borchers)\
**Post date:** [February 24, 2019, 8:27pm UTC](https://discourse.julialang.org/t/rank-revealing-qr-svd-decompositions/21155/1 "2019-02-24T20:27:23Z")

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Are there implementations of rank-revealing QR/SVD decompositions, resp. QR and SVD updating / downdating mechanisms in any Julia package?

See for instance:  
[1] Li and Zheng, A Rank-revealing Method with Updating, Downdating and Applications, SIAM J. Matrix Anal. Appl., 2005.  
[2] RankRev: a Matlab package for computing the numerical rank and updating/downdating, T.-L. Lin, 2016.