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geirev / Data-Assimilation-Fundamentals

This repository is a resource complementary to the book: Data Assimilation Fundamental: A unified formulation for state and parameter estimation
MIT License
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Errors in chapter 8 ？ #2

Open BeingHapppy opened 1 year ago

BeingHapppy commented 1 year ago

Dear professor Evensen, I am Yantong Wu, the student who asked you questions by email at Easter. Thank you very much for your new book. Our study team has been learning a lot from your new book. Today, when we read chapter 8, it seems we found two typos. (1) In Sec. 8.4, below Eq 8.25, it wrote " ...... anomalies A = Ai Ω−1", however, the Ω is iterative, so maybe "A" should equal " Ai Ωi−1"? ( "−1 " means Invert， I do not know how to write on the website). We read the slide you shared in GitHub, it is also "Ωi" not "Ω". image (2) In Sec. 8.9, Eq 8.47 and Eq 8.48 both with "+" symbol at the top right of the matrix, for example, "SS+", but we think "+" may be a Pseudo-inverse symbol, and the third row below Eq 8.51, Σ+UTE, the "+" may be a Pseudo-inverse symbol? We are not sure. image

Best wishes, Yantong

geirev commented 1 year ago

Thank you Yantong, these are typos that we will correct in the next edition. The + superscript is indeed another common notation for the pseudo inverse, but in the book we have decided to use a \dagger to denote the pseudo inverse.

BeingHapppy commented 1 year ago

Thank you for your reply !  

Yantong Wu @.***

 

------------------ Original message ------------------ From: "Geir Evensen"; Sendtime: Wednesday, Oct 19, 2022 8:48 PM To: "geirev/Data-Assimilation-Fundamentals"; Cc: "Yantong @.***>; "Author"; Subject: Re: [geirev/Data-Assimilation-Fundamentals] Errors in chapter 8 ？ (Issue #2)

Thank you Yantong, these are typos that we will correct in the next edition. The + superscript is indeed another common notation for the pseudo inverse, but in the book we have decided to use a \dagger to denote the pseudo inverse.

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