Serving the Quantitative Finance Community

 
User avatar
MCarreira
Topic Author
Posts: 64
Joined: January 1st, 1970, 12:00 am

Coin problems: your days of solving with pencil and paper are over

November 28th, 2012, 5:19 pm

Mathematica 9 - What's new
 
User avatar
frenchX
Posts: 11
Joined: March 29th, 2010, 6:54 pm

Coin problems: your days of solving with pencil and paper are over

November 29th, 2012, 8:43 am

What happen when the computer is broken ? Funny to see top star physicist researchers looking around desperately during electric black out
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

Coin problems: your days of solving with pencil and paper are over

November 29th, 2012, 8:53 am

QuoteOriginally posted by: frenchXWhat happen when the computer is broken ? Funny to see top star physicist researchers looking around desperately during electric black out In the olde days people used those precious moments for contemplation, code review and planning the summer holidays. Modern s/w hacking tends to be CLG (Compile, Link, Go).
Last edited by Cuchulainn on November 28th, 2012, 11:00 pm, edited 1 time in total.
 
User avatar
Vanubis1
Posts: 1
Joined: February 21st, 2011, 7:41 am

Coin problems: your days of solving with pencil and paper are over

November 30th, 2012, 1:01 pm

But I find the results in this example are wrong because it calculates the expected time for both HHT and HTT in the same algorithm with absorbing state (transition matrix=1)
 
User avatar
wileysw
Posts: 7
Joined: December 9th, 2006, 6:13 pm

Coin problems: your days of solving with pencil and paper are over

December 1st, 2012, 3:44 am

Vanubis1, the statements made on that page are misleading - the unconditional expected time for both patterns is same 8 tosses. what they meant to say, however, is:the average number of tosses to reach "HHT" conditional on "HTT" NOT being reached earlier is 17/3, while the average number of tosses to reach "HTT" conditional on "HHT" not appearing first is 14/3;this is of course just the classic "penney ante" paradox (e.g., HHT has the edge of 2:1 against HTT that would appear first, even HHT takes longer conditionally) and there are nicer ways to get the results much faster (search an old post here about Conway's leading numbers), but it is a very cool illustration of this firstpassagetimedistribution function.MCarreira, do you mind posting the actual distribution (if you happen to have the newest version already:P)?
Last edited by wileysw on November 30th, 2012, 11:00 pm, edited 1 time in total.
 
User avatar
MCarreira
Topic Author
Posts: 64
Joined: January 1st, 1970, 12:00 am

Coin problems: your days of solving with pencil and paper are over

December 1st, 2012, 3:33 pm

Do not upgrade !Serious problems in saving PDFs.For Windows serious problems with fonts (official email).
Attachments
CoinFlipSequences.zip
(36.31 KiB) Downloaded 106 times
 
User avatar
MCarreira
Topic Author
Posts: 64
Joined: January 1st, 1970, 12:00 am

Coin problems: your days of solving with pencil and paper are over

December 2nd, 2012, 6:55 pm

Workaround:Print as PDF (thanks to a friend who pointed this out).The whole thing now uploaded.
Attachments
CoinFlipSequences2.zip
(305.07 KiB) Downloaded 102 times
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

Coin problems: your days of solving with pencil and paper are over

December 2nd, 2012, 8:06 pm

QuoteOriginally posted by: MCarreiraDo not upgrade !Serious problems in saving PDFs.For Windows serious problems with fonts (official email).Can we revert to pencil and paper
 
User avatar
Traden4Alpha
Posts: 3300
Joined: September 20th, 2002, 8:30 pm

Coin problems: your days of solving with pencil and paper are over

December 2nd, 2012, 8:24 pm

QuoteOriginally posted by: CuchulainnQuoteOriginally posted by: MCarreiraDo not upgrade !Serious problems in saving PDFs.For Windows serious problems with fonts (official email).Can we revert to pencil and paper WARNING: insecure read/write/erase device pencil() deprecated. Use pen()WARNING: malloc(paper) failed: insufficient trees.
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

Coin problems: your days of solving with pencil and paper are over

December 3rd, 2012, 5:24 am

Quote"Dijkstra was known for his habit of carefully composing manuscripts with his fountain pen. The manuscripts are called EWDs, since Dijkstra numbered them with EWD as prefix. According to Dijkstra himself, the EWDs started when he moved from the Mathematical Centre in Amsterdam to the Technological University (then TH) Eindhoven. After going to the TUE Dijkstra experienced a writer's block for more than a year. Looking closely at himself he realized that if he wrote about things they would appreciate at the MC in Amsterdam his colleagues in Eindhoven would not understand; if he wrote about things they would like in Eindhoven, his former colleagues in Amsterdam would look down on him. He then decided to write only for himself, and in this way the EWD's were born. Dijkstra would distribute photocopies of a new EWD among his colleagues; as many recipients photocopied and forwarded their copy, the EWDs spread throughout the international computer science community. The topics were computer science and mathematics, and included trip reports, letters, and speeches. More than 1300 EWDs have since been scanned, with a growing number transcribed to facilitate search, and are available online at the Dijkstra archive of the University of Texas." QuoteYou see, another thing this alien resident of the USA could not fail to notice was the strong scepticism evoked over here by his 'I thought eloquent and convincing' pleas for a more mathematical approach to computing science and programming. An implication of that story is that, in the USA, the term "mathematics" has a meaning that differs from the one I grew up with. I am getting a feeling for how that divergence could occur; the role of education, which differs from country to country, has a lot to do with it. Is the use of Mathematica a replacement for pencil and paper?
Last edited by Cuchulainn on December 2nd, 2012, 11:00 pm, edited 1 time in total.
 
User avatar
Traden4Alpha
Posts: 3300
Joined: September 20th, 2002, 8:30 pm

Coin problems: your days of solving with pencil and paper are over

December 3rd, 2012, 11:21 am

QuoteOriginally posted by: CuchulainnIs the use of Mathematica a replacement for pencil and paper?Not until you can do this:QuoteIn[1]:= proc = TransitionMatrix[]Out[1] = Sometimes it's useful to go from a graphical representation (i.e., a sketch) to a mathematical representation. Maybe M10 will have sketch recognition tools.
Last edited by Traden4Alpha on December 2nd, 2012, 11:00 pm, edited 1 time in total.
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

Coin problems: your days of solving with pencil and paper are over

December 3rd, 2012, 11:27 am

QuoteOriginally posted by: Traden4AlphaQuoteOriginally posted by: CuchulainnIs the use of Mathematica a replacement for pencil and paper?Not until you can do this:QuoteIn[1]:= proc = TransitionMatrix[]Out[1] = Sometimes it's useful to go from a graphical representation (i.e., a sketch) to a mathematical representation. Maybe M10 will have sketch recognition tools.Why not treat it as a special kind of UML Statechart? Then you can use Boost *Meta State Machine* lib. Or by a directed graph?
Last edited by Cuchulainn on December 2nd, 2012, 11:00 pm, edited 1 time in total.
 
User avatar
Traden4Alpha
Posts: 3300
Joined: September 20th, 2002, 8:30 pm

Coin problems: your days of solving with pencil and paper are over

December 3rd, 2012, 12:11 pm

QuoteOriginally posted by: CuchulainnQuoteOriginally posted by: Traden4AlphaQuoteOriginally posted by: CuchulainnIs the use of Mathematica a replacement for pencil and paper?Not until you can do this:QuoteIn[1]:= proc = TransitionMatrix[]Out[1] = Sometimes it's useful to go from a graphical representation (i.e., a sketch) to a mathematical representation. Maybe M10 will have sketch recognition tools.Why not treat it as a special kind of UML Statechart? Then you can use Boost *Meta State Machine* lib. Or by a directed graph? That would work assuming Mathematica can take a graphical diagram (e.g., a .PNG or .SVG file) as an input and convert it to a transition matrix. Text or code definition of a graph is both laborious and error-prone.All input and output processes in Mathematica should have working inverses -- I should be able to start with a graphics object and invert that to it's mathematical form.
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

Coin problems: your days of solving with pencil and paper are over

December 3rd, 2012, 1:59 pm

QuoteOriginally posted by: Traden4AlphaQuoteOriginally posted by: CuchulainnQuoteOriginally posted by: Traden4AlphaQuoteOriginally posted by: CuchulainnIs the use of Mathematica a replacement for pencil and paper?Not until you can do this:QuoteIn[1]:= proc = TransitionMatrix[]Out[1] = Sometimes it's useful to go from a graphical representation (i.e., a sketch) to a mathematical representation. Maybe M10 will have sketch recognition tools.Why not treat it as a special kind of UML Statechart? Then you can use Boost *Meta State Machine* lib. Or by a directed graph? That would work assuming Mathematica can take a graphical diagram (e.g., a .PNG or .SVG file) as an input and convert it to a transition matrix. Text or code definition of a graph is both laborious and error-prone.All input and output processes in Mathematica should have working inverses -- I should be able to start with a graphics object and invert that to it's mathematical form.Graphviz?
 
User avatar
Traden4Alpha
Posts: 3300
Joined: September 20th, 2002, 8:30 pm

Coin problems: your days of solving with pencil and paper are over

December 3rd, 2012, 2:35 pm

QuoteOriginally posted by: CuchulainnQuoteOriginally posted by: Traden4AlphaQuoteOriginally posted by: CuchulainnQuoteOriginally posted by: Traden4AlphaQuoteOriginally posted by: CuchulainnIs the use of Mathematica a replacement for pencil and paper?Not until you can do this:QuoteIn[1]:= proc = TransitionMatrix[]Out[1] = Sometimes it's useful to go from a graphical representation (i.e., a sketch) to a mathematical representation. Maybe M10 will have sketch recognition tools.Why not treat it as a special kind of UML Statechart? Then you can use Boost *Meta State Machine* lib. Or by a directed graph? That would work assuming Mathematica can take a graphical diagram (e.g., a .PNG or .SVG file) as an input and convert it to a transition matrix. Text or code definition of a graph is both laborious and error-prone.All input and output processes in Mathematica should have working inverses -- I should be able to start with a graphics object and invert that to it's mathematical form.Graphviz?Exactly! But only the "dotty" tool counts toward the goal. There's tons of math -> pixels tools for converting a creating a mathematical object into a graphical representation. But the prerequisite for Mathematica becoming a replacement for pencil and paper is the inverse -- tools that convert a graphical representation into a mathematical object