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### [Lapack] Doubts regarding DGEQRF and DORGQR functions

 ```Dear Sir,I am an amateur with LAPACK and I am confused about using the CLAPACK functions DGEQRF and DORGQR. Assuming I have a (10 x 2) matrix as the input matrix, how would I call the above functions?From my understanding, the input matrix should be converted to a 1D matrix in a column-major arrangement. So the input matrix (say A) becomes a (1 x 20) matrix. Let,M = 10 (number of rows)N = 2 (number of columns)LDA = ? (Leading Dimension of A. How do I calculate this?)TAU = (1 x MIN(M,N)) arrayWORK = ? (If I choose LWORK = -1, what should be the size of WORK?)LWORK = ? (How do I choose this value? Is it intuitive?)INFO (just declared, not defined)__CLPK_integer info1 = dgeqrf_(&M, &N, A, &LDA, TAU, WORK, &LWORK, &INFO);These calculations give me the desired value of R (from A) but how do I calculate Q? I don't clearly understand the working from the comments in the code.I would greatly appreciate your help in this regard.Thanks in advance,Nevine _________________________________________________________________ Express yourself - download free Windows Live Messenger themes! http://clk.atdmt.com/MSN/go/msnnkwme0020000001msn/direct/01/?href=http://imagine-msn.com/themes/vibe/default.aspx?locale=en-us&source=hmtagline -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.cs.utk.edu/private/lapack/attachments/20061004/3706ea8b/attachment.html ```
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