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Unread 19-10-2016, 12:26
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Re: R Package for Downloading FIRST API Data

Quote:
Originally Posted by sirwin View Post
It takes my algorithm 9 seconds to produce the 2696 x 2696 A matrix
I like to call that symmetric positive definite 2696x2696 normal equations matrix the N matrix... to distinguish it from the 17842x2696 dichotomous design matrix A.

Ax = b .. overdetermined system of linear equations (has no exact solution)

N = A'*A
d = A'*b

Nx = d .. linear system of normal equations (whose solution is the least squares solution for Ax=b)



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