Thanks -- this one makes sense. (It is shuffles the multiplications into a
balanced tree so that the top-level multiplication is the product of all
the odds (=n) times the product of the evens.)
Sympy itself uses prime swing.
On Friday, May 16, 2014 9:50:57 AM UTC-7, Richard Fateman wrote:
You are right! So sorry! I copied the wrong program into my note.
Here is a correct version. (Again, Peter's article is fun to read...)
(defun ff(n m) (if (= n m) n (*(ff n (+ m m))(ff (- n m) (+ m m)
For this one, (ff 10 1) computes 10! and
does the following multiplications.
(ff
Gee, this is getting long.
Here's the deal on the improved factorial. Perhaps you just haven't
gotten large enough, or your multiplications are too slow, even for small
numbers.
Or there is something else odd about your program that I don't see.
Certainly n=20 is way too small
to be
Right, balancing the multiplication tree can be a win, for the reasons you
give.
But, I don't think your code snippet is doing any of that. If I run a
version (attached) that prints out the multiplies it evaluates, (fact 100)
gives:
(2 . 1)
(3 . 2)
(4 . 6)
(5 . 24)
(6 . 120)
(7 . 720)
Well, I wouldn't have used such colorful language, but I share
Prof. Fateman's skepticism on the utility of lgamma for computing
factorials.
I tried the expression as given, (see attachment, if you want to try
yourself or point out errors) and it begins to diverge from the correct
value at n=17
On Tuesday, April 1, 2014 2:58:34 PM UTC-7, Ondřej Čertík wrote:
On Mon, Mar 31, 2014 at 9:14 PM, Matthew Rocklin
mroc...@gmail.comjavascript:
wrote:
http://www.evanmiller.org/mathematical-hacker.html
I reference that blog post pretty often. I fully intend to reference it
FYI, my SciPy talk for SymPy was not accepted (it was accepted for the
poster session). My talk on conda was accepted, as was the SymPy
tutorial.
Aaron Meurer
On Tue, Apr 1, 2014 at 4:58 PM, Ondřej Čertík ondrej.cer...@gmail.com wrote:
On Mon, Mar 31, 2014 at 9:14 PM, Matthew Rocklin
I think your arguments are weak, though given the audience, perhaps they
would be appealing.
Here's what I think constitute good arguments for people to know about CAS.
Maybe even sympy.
1. Scientists, mathematicians and programmers all have a rich language and
context for
discussing the
Hi Richard,
On Fri, May 2, 2014 at 5:32 PM, Richard Fateman fate...@gmail.com wrote:
I think your arguments are weak, though given the audience, perhaps they
would be appealing.
Here's what I think constitute good arguments for people to know about CAS.
Maybe even sympy.
1. Scientists,
On May 2, 2014, at 11:23 PM, Ondřej Čertík ondrej.cer...@gmail.com wrote:
Hi Richard,
On Fri, May 2, 2014 at 5:32 PM, Richard Fateman fate...@gmail.com wrote:
I think your arguments are weak, though given the audience, perhaps they
would be appealing.
Here's what I think constitute good
On Mon, Mar 31, 2014 at 9:14 PM, Matthew Rocklin mrock...@gmail.com wrote:
http://www.evanmiller.org/mathematical-hacker.html
I reference that blog post pretty often. I fully intend to reference it
again in my talk (if it is accepted).
The interesting thing about the Factorial / Gamma /
I like that you emphasized the utility for numerics, I think that this is
likely to be a selling point for the SciPy crowd. I think that it's
correct to inform the reader about what symbolics are but I think that the
first couple of sentences (which do this) could be stronger/more direct.
Right
Last minute (this morning) I decided to submit a talk based around some of
my more esoteric programming projects, multiple dispatch, pattern matching,
strategies. I drew a lot of inspiration from SymPy when I was thinking
about these things so if accepted then I'll probably use SymPy heavily for
On Mon, Mar 31, 2014 at 11:32 AM, Matthew Rocklin mrock...@gmail.comwrote:
I like that you emphasized the utility for numerics, I think that this is
likely to be a selling point for the SciPy crowd.
Yes, this was very intentional. I may need some help gathering up some nice
motivating
I like this talk. It sounds similar to the talks you gave last year.
I've really been sold on this approach in the assumptions system, a la my
branch. In the old assumptions and the current new assumptions, to write
down a fact, you have to do a lot of logic. You maybe don't need to know
the
On 31 Mar 2014, at 20:29, Aaron Meurer wrote:
On Mon, Mar 31, 2014 at 11:32 AM, Matthew Rocklin
mrock...@gmail.comwrote:
I like that you emphasized the utility for numerics, I think that
this is
likely to be a selling point for the SciPy crowd.
Yes, this was very intentional. I may
That's a good point. One of the nicest things about symbolics, when you can
get it, is that it can make things drastically more efficient by doing
mathematical simplifications. Evaluating integrals symbolically is a nice
example of this (especially for SymPy, which has some pretty nice
algorithms
http://www.evanmiller.org/mathematical-hacker.html
I reference that blog post pretty often. I fully intend to reference it
again in my talk (if it is accepted).
The interesting thing about the Factorial / Gamma / loggamma example is
that to find the solution you need to find someone who knows
And regarding assumptions I agree with everything that you said.
On Mon, Mar 31, 2014 at 8:14 PM, Matthew Rocklin mrock...@gmail.com wrote:
http://www.evanmiller.org/mathematical-hacker.html
I reference that blog post pretty often. I fully intend to reference it
again in my talk (if it is
Here is the detailed abstract I have so far for a talk for SciPy. Any
suggestions are welcome. The deadline is April 1 (probably 5 PM central or
thereabouts). I roughly based it on the matplotlib talk from last year
http://conference.scipy.org/scipy2013/presentation_detail.php?id=211.
Symbolic
20 matches
Mail list logo
