1,002 reputation
716
bio website math.lsa.umich.edu/~speyer
location Ann Arbor
age 34
visits member for 2 years, 7 months
seen Dec 17 at 13:52

Associate Professor of Mathematics at the University of Michigan. My research interests are in combinatorial algebraic geometry, particularly Schubert calculus, matroids and cluster algebras. I also enjoy thinking about number theory and computational mathematics.


Nov
25
awarded  Critic
Jun
5
answered Unexpected result from Map
May
7
awarded  Yearling
Jan
28
comment Discriminant of Characteristic Polynomial
What kind of entries does this matrix have? Integer, floating point, symbolic?
Jan
13
answered How can I complete a correlation matrix with missing values?
Dec
17
answered No response to an infinite limit
Dec
11
awarded  Autobiographer
Dec
3
comment Why does Mathematica choose branches as it does in this situation?
This issue also turned up here: mathematica.stackexchange.com/questions/24613
Jul
26
awarded  Good Answer
Jul
25
awarded  Nice Answer
Jun
4
comment How to split compound polygons into convex polygons?
dma.fi.upm.es/docencia/trabajosfindecarrera/programas/… is a very nice exposition of both a triangulation algorithm and the Hertel-Mehlhorn algorithm.
May
15
comment FourierSeries for rational function looks wrong
FourierCoefficient[1/(x^2 + 1), x, 1, Assumptions -> -Pi < x < Pi] gives the correct answer.
May
15
comment FourierSeries for rational function looks wrong
Edited my example to use FourierCoefficient, so that I don't have to muck around in the interior of FourierSeries output. Thanks!
May
15
revised FourierSeries for rational function looks wrong
added 875 characters in body
May
15
answered FourierSeries for rational function looks wrong
May
7
awarded  Yearling
May
1
awarded  Necromancer
Apr
25
comment How to improve the performance of solutions to Project Euler (#39)?
Here are the list of all "record setters", perimeters which achieve higher values than any previous perimeter, for $n \leq 10^6$: {12, 60, 120, 240, 420, 720, 840, 1680, 2520, 4620, 5040, 9240, 18480, 27720, 55440, 110880, 120120, 166320, 180180, 240240, 360360, 720720}
Apr
25
comment How to improve the performance of solutions to Project Euler (#39)?
For $p \leq 10^6$, the answer is always of the form $2^a \times 3^b \times 5 \times 7 \times 11 \times 13 \times \cdots \times p_r$ for some $(a,b,r)$. If we could figure out the pattern in the exponents $(a,b)$, there might be a much faster method.
Mar
28
asked Why is Flattening a CoefficientArray so slow?