KaizenToday

Fair coin from biased

kaizentoday — Wed, 23 Jun 2010 11:48:09 +0000

If a cheat has altered a coin to prefer one side over another (a biased coin), surprisingly the coin can still be used for fair results by changing the game slightly. John von Neumann gave the following procedure:

1. Toss the coin twice.
2. If the results match, start over, forgetting both results.
3. If the results differ, use the first result, forgetting the second.

IOI – indication of interest

kaizentoday — Tue, 18 May 2010 14:45:26 +0000

Turn Off Nagle (Windows)

kaizentoday — Sat, 03 Apr 2010 10:24:08 +0000

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSMQ\Parameters
Add a new DWORD value:
TCPNoDelay=1 (DWORD value, 0 to enable Nagle’s algorithm, 1 to disable, not present by default)

Markets – 02/04/2010

kaizentoday — Sat, 03 Apr 2010 10:23:22 +0000

Euro/Usd a -0.2% dia.

Ao sair relatório de emprego dos EUA, criados ~170.000 emprego, mercado reage com muita volatilidade. Noticia positiva indica que EURO/USD vai descer. No entanto, o movimento descendente só se verifica algum tempo depois.

Euro acaba o dia a -0.8%.

Markets 31/03/2010

kaizentoday — Wed, 31 Mar 2010 12:33:46 +0000

Euro/USD (-0.5%) e Petroleo caem em reacção aos bons resultados do relatorio de confianca dos consumidores nos EUA.
Euro/USD sobe 0.5% no dia seguinte (14:00) a antecipar relatorio de emprego nos EUA.

10 min antes de sair relatorio EURO/USD sobe. 20 min depois já subiu 0.2%

Ouro vai aos +0.72% do dia em reacção exagerada e rapidamente cai para os 0.66% (Vendi)
Ouro sobe aos $1113.5 e cai para os $1112.4 poucos minutos depois.
Petroleo sobe para os 83.35 em reacção à queda do dolar mas rapidamente cai para os 83.22.

Relatorio sobre procura do petroleo daqui a 2h promete.
Procura deverá estar a subir apoiada pela recuperaçao economica. Preco deverá estabilizar até la por volta dos $82.95.

Perl – Things that make my life easier

kaizentoday — Wed, 24 Mar 2010 19:48:26 +0000

-e execute. The LAST option

-n while(<>){..}

-p print $_ at the end

-a splits the string, spaces and puts the columns in @F

-F: splits using character :

Bonds & Yield

kaizentoday — Wed, 24 Mar 2010 19:36:45 +0000

Bonds price is affected by interest rate.

Callable bonds – the issuer of the bond can redeem the bond. Sometimes it has to buy back the bond (sometimes the call price is the par value/face value).

Nominal yield – the rate of return stated in the face of the bond

Current yield – the rate of return someone would make if bought the bond and sold it after on year. Takes into account the actual value of the bond

Maturity date – The latest date on which the issuer have to pay back the principal

Idioms I should use more often (2)

kaizentoday — Sun, 21 Mar 2010 11:49:46 +0000

ostream_iterator input(cin);

ostream_iterator

string first_string = *input++;

copy(input.begin(), input.end(), output.begin());

Idioms I should use more often

kaizentoday — Sun, 21 Mar 2010 11:41:55 +0000

for_each(InputIterator, InputIterator, Function); // Function being a function or object with operator(). Can have object with state

OutIt transform(InpIt, InpIt, OutIt, OutIt);

// algorithms that receive InputIterator are one-pass algorithms

fill(ForwardIterator, ForwardIterator, const T& value);

C++ typename keyword

kaizentoday — Sun, 21 Mar 2010 11:10:56 +0000

Qualified name – one that specifies scope (for instance, with std:: in std::cout)

Dependent name – name that depends on a template parameter (like list::iterator this_name). The same for Dependent Types.

Before a qualified name that refers to a type put ‘typename’. Otherwise the name is treated as a non-type.

typename T::iterator* it; // it is a pointer to some T::iterator type

T::iterator* it // T::iterator multiplied by it. T::iterator may be a static

typedef typename T::iterator it;

typedef typename Alloc::template
    rebind::other element_allocator;
     // template must precede the last component of the template name