1,166 reputation
413
bio website stanford.edu/~vkl
location California
age 29
visits member for 4 years, 3 months
seen 4 hours ago

PhD in EE (optics/physics/computational stuff). I mostly answer questions related to math, geometry, and numerics here.


1d
answered Characterize stochastic matrices such that max singular value is less or equal one.
1d
answered Can $A$ be singular
1d
answered Sum over all possible combinations of a Cholesky decomposition
Oct
23
comment Why for random matrix one of eigenvalues is so big?
If you try the example (Matlab: A=rand(64);D=eig(A);scatter(real(D),imag(D))), you see that there is only one. OP must be plotting eigenvalues for several matrices of each size.
Oct
23
comment Parametrising the unit circle without sine and cosine
What about the Weierstrass parameterization: en.wikipedia.org/wiki/Tangent_half-angle_substitution
Oct
23
answered Why for random matrix one of eigenvalues is so big?
Oct
22
answered Find an orthonormal basis for W and $W^{\perp}$
Oct
21
comment Rectangle division into shapes and connecting adjacent shapes with non-intersecting lines
Well, already, the line connecting the red and yellow centroids cross the line connecting the green and blue centroids. You need to be more specific about your question.
Oct
21
comment How to Compute the Torsion and Curvature of a Parametric Curve
Can you please give the equation of the curves that you are trying?! I would like to verify your claims.
Oct
20
answered Fallacy - where is the mistake?
Oct
20
comment How to Compute the Torsion and Curvature of a Parametric Curve
What is a "reasonable" curve to you? What did you try this on?
Oct
20
answered Area of triangle interior to parallelogram
Oct
20
comment Estimation of superexponential integral
I am curious about the context in which this problem arises, and also the required level of precision.
Oct
14
answered Eigenvalues of 3D rotation matrix
Oct
14
answered How to find LU factors of a matrix when diagonals are changed
Oct
13
answered Numerically stable extraction of Axis-Angle from Unit Quaternion
Oct
6
answered Sketch the set of points determined by $\lvert z-i \rvert^2 + \lvert z+i \rvert^2 \le 4$
Oct
6
comment Is diagonal of sum matrix of rank one matrix and circulant matrix.
If that is the form of your $u$ and $v$, then if $F_n$ are Fourier matrices, then the answer to (2) is no, since any multiple of an elementary vector $e_j$ is a linear combination of all columns of a Fourier basis.
Oct
6
revised Is there an easy formula to calculate this angle?
Fixed final equation
Oct
6
suggested suggested edit on Is there an easy formula to calculate this angle?