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5 votes
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Under what circumstances Is a symmetric matrix representable as a Coulomb matrix?

Question: I am exploring a neural network architecture inspired by physical interactions, where each neuron has associated "mass" and "position" vectors. The weight matrix between ...
mathoverflowUser's user avatar
0 votes
0 answers
36 views

Conjugate gradient-like algorithm with multiple search directions

I am solving an $n*n$ system $Ax=b$ in CUDA where $A$ is a sparse matrix. Currently I am solving it using the conjugate gradient algorithm. I have noticed that $Ax$ where $x$ is $n*1$ has roughly the ...
SRB121's user avatar
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2 votes
1 answer
421 views

Is it possible to obtain orthogonal (but not normalized) vectors after QR factorization?

After QR decomposition of a matrix, $M$, the columns of Q are orthonormal. Is it possible after obtaining Q, we recover unnormalized column vectors from $Q$? For example, the matrix M has the ...
ACR's user avatar
  • 879
-2 votes
1 answer
213 views

Solving a difficult equation for a variable?

I'm trying to obtain the maximum likelihood estimate of the parameters for a model I'm building. I have constants $\sigma$, $\mu$, and $q_0$; a boolean matrix $\alpha$; and vectors $A, \beta, r, d,$ ...
rhombidodecahedron's user avatar