The family used here is 20x20 "anti-tridiagonal" matrices (an upside-down tridiagonal matrix) with population {-1, 0, 1}. 100 million matrices were sampled.
For anyone curious about the rounding error in the skew-symmetric tridiagonal matrices eigenvalue plot. This shows a close up of the rounding error (a different family of matrices but the same principle applies).
The red circles have radii of eps^(1/m) (machine epsilon) giving the expected rounding error for eigenvalues of multiplicity m in double precision with m=15 for the outermost circle.
Today's @BohemianMatrix computation, by my student Aaron Asner: the eigenvalues of all 31 by 31 skew-symmetric tridiagonal matrices with population 1 and i. Over a billion matrices; computation in parallel on a 64 core machine took 85 hours. The center rose is rounding error!
The work (with @stevejtrettel and Kate Stange) I have been trailing for a while on Algebraic number starscapes (the patterns in polynomial roots) is now up on the arXiv; https://t.co/tgib6T2FVQ It is a math paper, but the images should be accessible to all!
Happy to announce that our Generalized Standard Triples paper (a part of the @BohemianMatrix
Project) has been revised. Thanks @LeiliRafiee and @euniceyschan
and to @tisseurf
for the feedback! https://t.co/nyE3iJBmLg
Ok enough about other people's talks. I'm giving two: one Thursday, a general introduction to Maple @maplesoft and one Friday where I will show how to make @BohemianMatrix pictures like this in Maple.
In my upcoming (Dec 12/13) masterclass in Maple @NewtonInstitute, participants will learn how to make @BohemianMatrix pictures like this. This is hybrid symbolic numeric computation. @maplesoft [5th roots of unity, 7 by 7 symmetric tridiagonal 0 main diagonal]
MATLAB's creator Cleve Moler will be taking part at the minisymposium on "Bohemian Matrices" at @ICIAM2019 on Friday 19. Do not miss it! @MathWorks#weloveMATLAB
SPOILER AHEAD 👇🧐⚠️
https://t.co/FKYTzxME1z