1,561 reputation
615
bio website suitdummy.blogspot.com
location Cambridge, MA
age
visits member for 2 years, 1 month
seen Apr 2 at 14:38

I once launched swi-prolog and asked it a question:

ely:~/home$ prolog
Welcome to SWI-Prolog (Multi-threaded, 64 bits, Version 5.10.1)
Copyright (c) 1990-2010 University of Amsterdam, VU Amsterdam
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to redistribute it under certain conditions.
Please visit http://www.swi-prolog.org for details.

For help, use ?- help(Topic). or ?- apropos(Word).

?- love(math) is unrequited.
true.

Nov
11
awarded  Nice Answer
Jul
22
awarded  Nice Answer
Jul
21
comment Fastest numeric method for ODE
Also, FYI this question is probably better suited for either SciComp or Stack Overflow. It's not clear that this is due to your chosen algorithm. It could easily be due to an inefficient C implementation. If you post some code along with the question at either of those other sites, you'll almost surely get better help... and folks on those sites will also be able to suggest other mathematical algorithms to try if indeed that is the right way to solve the problem.
Jul
21
comment Fastest numeric method for ODE
Are you sure it is Euler's method that is slowing you down, and not the implementation? What language are you using? Is it a built-in or library function? What is your data set like? What sort of machine are you performing the calculation on, and with how much RAM? When you say it is 4-8 times too slow, what is this relative to and what timing benchmarks have led you to this conclusion?
Jul
21
accepted Necessary and sufficient conditions for a matrix to be a valid correlation matrix.
Jul
20
asked Necessary and sufficient conditions for a matrix to be a valid correlation matrix.
Jul
17
awarded  Necromancer
Jul
4
comment Can I use the geometric mean instead of the arithmetic mean to calculate the covariance between yields of different stocks?
Normally what you are calling "yield" is called price return (in this case, daily price return). Also make sure you're computing the price of the later day minus the prior day, not vice versa (that is, subtracting 1 after dividing is equivalent to subtracting the prices, then normalizing to the prior day's price).
Jun
8
awarded  Caucus
May
11
comment Does a random action have probability?
Probability is in the mind!
May
7
revised Math Database For Problem Descriptions In An App.
edited body
May
7
revised Selecting numbers on a number line where distribution tends to cluster at one end.
added 691 characters in body
May
7
answered Selecting numbers on a number line where distribution tends to cluster at one end.
Apr
29
comment Probability and Axiom of Choice
Cox's Theorem prevents you from distributing "indifference" among infinitely many things. That's not a state of knowledge one can possibly have, and probability is in the mind
Apr
29
comment Probability and Axiom of Choice
You should read this paper and the Freiling paper mentioned in it.
Apr
25
comment Fourier transform probability distribution
It does seem from Box-Muller that you'd be computing a weighted combination of normal components, and so the result ought to be normal.
Apr
24
comment Undergrad Student Trying to Figure Out What to Study
Of course you should give weight to your preferences. I am merely suggesting that most people give too much weight to what they currently enjoy doing, and not enough weight to the real externalities involved. Obviously, do not do something you don't enjoy. But surely most people enjoy more than one thing. I mostly think that when someone says, "I do what I love", they haven't thought about it very much. Surely you don't love just one vocation. It's a fallacy that is unique to high standard-of-living countries that we teach our young to focus almost exclusively on imagined preferences.
Apr
23
answered Undergrad Student Trying to Figure Out What to Study
Apr
22
comment Efficient principal pivots
You definitely want to ask at scicomp.stackexchange.com. Since this is mostly an implementational / speed issue, they can probably help a lot more.
Apr
22
comment Weird conclusion about variance/covariance from differentiating
In the sense that it minimized portfolio volatility.